I usually look for a length of about 3"-4"you dont want to big or you could easily cut your self when doing the lung cavity. you dont need no big honkin davy crocket/ crocodile hunter (no this is a knife) kind of thing.

I dont think the gut hook is necisary and it does not work a great deal better in my oppinion. you cant hardly find a knife w/o the gut hook now adays (at least in basspro/cabelas).

FYI: I bought a couple in the wal-marts. still have them. they cost no more than about 10 bux and work great. I just make shure to check them at begining of season, and sharpen them up if need be. they are the winchester searies. nice knives