While I don't have as much experience as some posters, I will add my voice and my .02. Side windows on a mask have been a distraction and I found them annoying more than helpful. My DI wore one just during classes so he could have peripheral vision to catch problems. But he told me that that is the ONLY time he used them. For the same reasons.
If you have vision problems, don't forget to take care of that when you get your mask. You want to have a clear view of your surroundings AND your gauges. Don't scrimp. The view is the reason you are down there, the other stuff is to get you there.
As far as fins and boots, fit is not just king, it's everything. It all has to work together. You want to feel totally comfortable and at home with everything. If something needs to be changed, change it and get it right.
+1 on removeable snorkels. Although nowadays I find it easier just to tuck it into the cummerbund like a wallet on my right side so it's right there out of the way. Just seemed to evolve that way and it works quick to put it away and quick to get it out. Try different things and see what works for you.
