The RIP is a pretty cool piece of SR-101, but I don't think it will give you a true sense of the Rats field capability. You can stab with it, but you can't cut, slice, dice, hack, chop, whittle, slash or thrash with it. You'll love it, no doubt, but get yourself a Chopweiler when they become available again. I vote for Muddy by the way. It is one bad-a$$ blade that chops like a champ. This blade will give you a true representation of SRKW's fit, finish, design, handle material and steel properties. It will also cause your bank account to go to $0.00 VERY fast

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As for sheaths, Guyon mentioned the Spec-Ops. He really loves those, so they must be good. Can't really beat the price either. If you are more of a leather guy, you can contact Chuddy Bear and he can get you a sweet pair of cowhide pants to you FAST (generally a couple of days). Either way, you don't need to send your knife off for fit as we know the Spec-Ops fits and Chuddy has already done Chopweiler sheaths and has a template.
Don't hesitate when the Choppers show up at the store. They will sell out quick. Do it man, just do it!