You can do all that with a RB. Parts are not expensive, you just have to know were to find them. A lot if the parts fit other nissan engines here in the states. You can find anything on the internet. In fact the part prices are getting cheaper. Servicing a RB isn't any harder than working in a L motor. It's all nuts and bolts. It sounds like your talking yourself out of it. If you know what your doing the rb isn't any harder to work on and is reliable as any motor available.
I had 3 sets if triples on my stroker now that was a bitch to tune. Jets were hard to find and had to be ordered. Jets,tubes mains,pilots,chokes all times 6 =$$$$