The dirty30 would be a very good choice.
properly balanced and an aftermarket balancer ross/ati they will rev to 8k
be considerably cheaper then a stroker kit too
Go with a big single to save alot on buying 2x the turbos,manifolds,etc
Have a read through Cubes thread. He has a low mount rb25/30 making 400hp? on stock manifolds (i think)
however engineering a rb30 and licensing it these days might be more of an issue over a rb25 with a 2.8 stroker