not sure about the prices, we pay 900 for them in AUS, not sure if its 900 in NZ or what the go is.
i think clearancing will be all,you will have to have a decent search on the hydraulic lifters in the head.
as i said before, depending, some people have issues at over 350rwkw,i think larger cams may impact also? dont quote me on it though.
in the below thread are all the RB cam specs
http://www.skylinesaustralia.com/forums/post-a282987-