Crabs in LL, puks, and beastmen camps, and Aldgoats in Thanalan are all pretty good SP (I think I was getting about 250 SP per Aldgoat on my THM vs. 34?) and they die pretty quickly. The camps are a problem for those less than R34 though since the most frequent mob (at least in the Thanalan camp) are R42. The R30-ish mob doesn't spawn as often + there's only 2-3 of them.