I have (intentionally) used almost every RMK made on field work...just-cause. Some worked better than others but still a lot of choices would be a matter of personal taste.
Here's a brief review and "possibles" to think about. Duke has already expounded on RMK's #8. Whether old or new style, both T&B's work quite well. Other 3/16" stock knives perform admirably, again as Duke mentions, the #28-4 1/2" just to add one to the mix.
Rob wants a Model #26-4", Pathfinder, and they need to be in the discussion...4 sure. Here's a couple of the "above" to aid in your "visual" thought process....
Stay Sharp, Capt. Chris