I think any sharp, fixed blade broadhead will work very well. The key is putting it in the right spot. I've attached a couple illustrations to help you get that right (most 3-D turkey targets have the vitals in the wrong spot!). Study the photo and use that mental x-ray image for your shot.
We could fill hundreds of pages with advice on turkey hunting, and still never cover all the little details. I can offer some tips that I think will help:
1. Get some turkey hunting videos. You will learn a lot from seeing how they setup and call. The Primos "The Truth" series are very good, as are the HS "Cuttin' 'n' Struttin" series.
2. Buy a ground blind. It will be VERY difficult to shoot a turkey with a bow if you are not in a blind. You could also build a permanent blind in a good spot, but ground blinds are nice because they're portable and keep you dry if it rains.
3. If you are hunting from a ground blind, you won't need full camo. But make sure you have a face mask/face paint and gloves. If you will be out moving around, make sure you have full camo. And remember even if you are covered head to toe in the finest camo, if a turkey sees you move you're busted.
4. Get a decoy, or two. Stick with a hen or a hen/jake decoy. Avoid the full-strut type decoys until you are only interested in shooting boss toms. The full strut decoys can sometime spook off subordinate birds.
5. Buy a couple calls and practice. The easiest calls to use are the little push-peg calls. You can operate them with one hand and they sound pretty good. I really like a slate call with a wooden striker. Won't work when wet, but they are pretty user friendly and can make a wide variety of sounds/volume levels. It is important to be able to make some basic calls, but don't think you have to be an expert caller to get a turkey. Just a few clucks at the right time can be all you need. Box calls are excellent too, but they are loud and you must resist the temptation to overcall with them. If you are able to use a mouth call, that is the absolute best call for an archer, because it is hands free. You don't need to be an expert with it, just a few soft yelps and some clucks.
6. SCOUT. This is, hands down, the most important item. Get into the woods as many mornings as you can before you hunt. Start a few weeks before the season. Don't bring your turkey calls, just spend time sitting before dawn and listening to the birds gobble on the roost (some mornings they don't gobble much, at all). Learn where the turkeys roost. Slink around with a good pair of binoculars (and full camo!) and shadow your turkeys. Where do they go after they come down from roost? Do they travel the same route each time (read: ambush!). Do they head to a field to feed/strut? Where do they enter/exit the field? The more you know about the property and where the birds will be on it, the higher your chances of success.
7. Buy a crow call. Blowing a crow call often gets a tom/jake to gobble. It is called a shock gobble. This is a great way to get a fix on a bird’s location without having to make hen sounds.
8. Remember you can't stalk a turkey! You must either call them to you, or be on their travel path. A turkey's eyes or outstanding, especially in catching movement. Stalking a turkey is nearly impossible, and it can be dangerous if there are other hunters around. If you see a turkey and want to try to get it, try getting ahead of where it is going and doing some calling.
9. Calling - less is more. There is a time and a place for loud aggressive cutting and yelping. But, more often than not the soft yelps and clucks are more effective.
10. Believe. Believe there is a turkey coming to your call, and a turkey just around every corner. In the videos, they often come in gobbling and strutting. That is awesome when it happens, but just as often they will slink in quietly and seem to appear from nowhere. Just because you do not hear a gobble in response to your calls, doesn't mean a tom is on the way!
11. Patience and perseverance - the two most valuable assets in a turkey hunter. It's nice if you are a champion caller and a can shoot through the eye of a needle at 20 paces, but if you give up easily the turkeys will beat you every time. I can't remember how many times I've dragged myself out of bed dreading another ass-whoopin', and walked out carrying a tom and a smile. :D
12. Turkeys will very rarely cross water, fences, deep ditches, etc. to come to calling. Know the property you hunt and never set yourself up with a barrier like that between you and a gobbler.
13. Read some magazines. A lot of the turkey hunting magazines how some good, basic articles to help you get started.
14. Get there early. If you are hoping to get a bird right off the roost, don't be afraid to be setup well before dawn. I'd rather be an hour early than 1 minute late.
15. Hunt. Don't pack it in and go for breakfast at 8am because you didn't get a bird right off the roost. and if you are just too tired to get up, have to work, need to watch the kids, or whatever... don't hesitate to go out at 8am, or 9am, or 10am. Every minute of legal hunting time is valuable and you can't kill a turkey if you aren't out there. If killed just as many turkeys at 11am as at 7am.
16. Stick and stay. If you are setup where turkeys might be, stay there. Bring a snack. Have a nap. Just be there. Call softly every 10-15 minutes, and make some louder yelps every hour. Turkeys don't have watches and have a funny way of showing up later than expected. They can show up early too.
17. SCOUT! (get it?)
18. Enjoy the journey. The spring turkey woods is a magical place. Soak it all in and remember you will come home empty handed more often that not.
19. Don't hunt one bird. I have seen too many friends do this - you see a nice tom and spend the rest of the season determined to kill him, only to end up putting your tag in your photo album at the end of the season. If you have more than one good place to hunt, don't get too hung up on one particular bird.
20. If it is raining, set up on the edge of the field. Put out a decoy or two, and call softly every 10-15 minutes. Turkeys come to fields in the rain, so be patient. If you have seen birds/tracks in the area, they will be there eventually.
21. Don't forget to take photos and post them on TradGang.
I could go on forever. Best is to get just out there and learn from your mistakes. As long as you don't make the same mistake twice, you will eventually succeed! GOOD LUCK!