Perhaps I'll check out some of your suggestions. I already own Scalps (not as violent as everyone says, but it is good. Bruno Mattei is on of my favorite horror/exploitaion directors so I'm already inclined to like it,) Shanghai Joe (this is a good one, pretty violent) Shoot the Living... (a little boring but good none the less,) and Night of the Serpents (definitely a good one!) Oh yeah, Keoma should fit in too... Keoma is awesome.
California, Mannaja, Matalo do seem interesting from what I've seen, but I haven't actually seen the films... perhaps I'll have to check them out... As far as Yankee goes, I've never even heard of it... By your description, I think I'll add that to my wantlist as well!
Thanks for your input!