As an elk and deer guide I used to use knives called Havalon. They have removable blades. There are many different styles. I use the stag with 60A stainless steel blades. They were invented by a surgeon. Each blade comes sterilized individually in a foil pack and is scalpel sharp. You have to be very careful changing blades until comfortable. I highly recommend.
Those do look very interesting, a foldable blade with what looks like much better grip/handles than most X-acto options. Their 22 stainless steel blades @ $18 per 100 sure is priced right. The knives are pricey (and mostly out of stock), but their cheapest knives (piranta-stag black) is $44 and in-stock. I'm not looking now, but maybe when I'm through most my Schicks.
***UPDATE*** just took a look on Ebay, they have Piranta knives at much lower prices. I picked up a Bolt for almost half price; it's a pink handle, but I'm confident in my manhood
It comes with 12 #60A blades. I think the 22 blades will be a better choice, but I'm going to wait until I see what the 60s do for me.