RB's aren't that hard to find, actually, but you need to get lucky to get one in good condition... I've seen one or two RB25DETs and an RB26DETT at the engine shops in Evangelista.
Most popular for RWD here are the RB's and the SR20DE's and DET's, with some of the old-schoolers going for the tried and true 4AGE and their variants (the big Nissan sixes won't fit, and the 4AGE gives similar output to the SR20DE...)
But the tuning scene is mostly the common 4AGE or B16A swaps, or the occassionaly SR20DET and 4G63T swaps. It's often hard for the budding tuner to find the right suppliers here, or to find people who know certain engines well, but if you have a hankering for a particular motor or car, the car club forums (grupotoyota, protegetech, clubmitsu, nissanbayan, hcp (is it?), fordclubph (although our knowledge base is still small)) are a HUGE help.
