so... little background (as i understand it) on the "RAT" knives:
There's a company called "Ontario" and a company called "RAT" (short for Randall Adventure Training, i think). Once upon a time, Ontario put out a RAT series of knives inspired/created/made by RAT. As time went on, the two had a falling out. Ontario may or may not be continuing to make a RAT series of knife (RAT has asked them to stop as their business agreement is no longer). I think it's caught up in legal land right now...
SO.... conventional wisdom says that there are Ontario RAT knives. I have an Ontario RAT3 and Ontario RAT5. they are very good knives and i've been very happy with them. From what i've read, if you want the "real" mccoy nowadays, go to the source and buy from RAT. there may or may not be QC issues with the ontario rat line (or maybe that's just what RAT would like people to believe). Regardless, if you want to support the true "maker" and inspiration of the RAT series, go to
www.ratcutlery.com My very cursory impression is that RAT is the little guy and Ontario is the big guy trying to take advantage/bully them. then again, RAT may just have a better PR machine.
My ontario RATS are made of 1095 steel which i've found no problem with. I'll also say i haven't really put them through the paces enough to determine long term durability/quality. each came somewhat dull and had to be touched up to my standards. I think you can get the RAT cutlery knives in D2 steel which some might proclaim is better. I leave that debate to your "search" button.
In conclusion, there are some nice knives out there from the Ontario/RAT people. There's a RAT 3, 5, and 7 (roughly corresponding to blade lengths). there's an RC3, 4, 5, and 6 if i recall. do your own homework and figure out what's best for you. i'd imagine between those 2 product lines, there's as big a knife as you would want to carry.