I have played GW games in the past like Necromunda and Mordheim which seem to be the engine that LotOW are derived from. I have also played LotOW... so I think that you should give .45 Adventure a try... they are certainly not more complicated than LotOW. Also Howard Whitehouse's rules are pretty good too... Astonishing Tales I believe they are called. I just purchased Astounding Tales, which is the scenario book for his rule set.