One of the greatest gifts my wife has ever given me was to have an electrician come in and re-wire my shop. A house down the street had a fire due to bad wiring and really made us think. I had way too many lines and too much stuff on given circuits. I ended up with three separate circuits with two outlets per wall, master circuit breakers and individual safety ground trips on each outlet, plus all new overhead BRIGHT lighting... all done to code and city inspected.
I opted not to go for 220. I have a shop full of Grizzly machines A couple of them are big guys that come able to be wired either way. I work in my shop a lot and build a lot of bows. I know that 220 would be nice, and a bit cheaper, but I just don't think it's necessary for my level of work. Every now and then I forget and hook too much up to one outlet, making it trip. I cuss, but you know what? It feels good! I know I'm covered.
So, my advice is, whichever way you decide to go voltage-wise, have it done. The complete job cost the price of a couple of big tools, but I hope to work in that shop the rest of my life. It's a heck of a lot nicer, and safer, place to work than it used to be.