The pelican, as hunt it noted, is the best out there.
I think the case I have runs around 50" and is under the 62" regulation size. If it's 62.5" you are technically "over"...I suppose it would depend on the person you were dealing with at the counter. Personally I'd go with a different model to avoid any issues.
Locks: You will need the universal locks. Yes, it stinks, but it's what you will have to do in this day and age.
Foam: I've used 1" thick stuff. You can draw the outline of the profile of your bows and cut it out with a razor knife--you may need a few layers of foam to get to your riser's thickness. Glue this cut out layer(s) on top of a solid piece of foam, which will be the bottom.
Also don't forget to cut out a spot for your quiver, tabs, miso items...et cetera. Take a look at the Blackwidow website (under accessories) to see what they came up with--it's really quite well thought out.
24 arrows? Use the lid for your arrows. You'll need to come up with a way to hold them in place. Again check the BW site for inspiration. They did it right.
Something I did to my Pelican case was to make it look kinda junky. To my way of thinking if the case looks good it's going to contain something "good" inside for a would be thief.
I randomly spray painted the case, added duct tape (to make it look like the case is falling apart). Just trying to make the case not attract attention--especially for something that looks like it might contain a rifle or two.
Good luck.
J