If your car is auto do not bother as the box lets go at anything above 500whp. If you cap it at that with tuning you just going to have peaky power band vs the modified twins.
There are no known RHD kits. So it has to be custom. If you insist on doing it Rob Beck of RB turbos sells the special flanges that attach to the heads and that is a start. Lambda placement and trickery is important and it will make or break the kit. Get a yank tuner on board if you get the pipe work right because no one local will tune it or be willing to take a shot at it. All of this assuming a decent size I.e. Greater in flow than a set of RB's can fit.