Thought I'd cover the low end price-wise.
Don't know the blade measurements of the smaller CRKT M16s. If you get one with the flipper, you can forget about thumbstuds altogether. Flipper is much quicker. They're one of the better knife values out there, IMO.
The larger CRKT LUS has a 3" blade, opens very easily and smoothly. A very good value also, and it isn't black.
I'm extremely impressed with teh Spyderco Native. I think it one of the most versatile knives out there. It isn't designed for combat, but should prove adequate at it, if necessary.
Except for the thumbstud -- too small for unknown reasons -- the CRKT Apache 2 would be ideal. I think it is one of the better stabbing combat knives out there, with enough belly to do some slashing as well. Is is on sale for extremely low price at Smoky Mountain Knife Works right now. $20. It has aluminum handles and ATS34 steel.
Last, but by no means least, the smaller CRKT KFF has a 3" blade, I believe. The knife is designed for combat, pure and simple.
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