If you really want "action packed" and very palpable lethality get Aces and Eights. Its also scaled, so you can keep it as simple as you want, and add whatever complexity you want. First Western that really "grabbed" me, and I have tried Savage Worlds, Go Fer Yer Gun, GURPS, Boot Hill, and a couple of others, and even though they were fun, none were as action packed and on the edge of your seat lethality. Heck, even the brawls and chases were exciting.
However, we all know tastes vary, so I can only hope your tastes are similar enough to mine to like it best.