Hmmm, thoughts are pouring into my head now.
R32 - supercharged = lowdown grunt and no turbo lag and cheaper than a Turbo conversion but not generally as reliable as one
R36 = More n/a power, stock engine and the delicious V6 howl. Uprated rods and pistons would allow a higher redline and even more power. Also would be a "halfway house" to the HPA/HGP twin turbo conversion with 640bhp
Edition 30 engined R32 = Could be a winner with a Garrett GT30 or 35 turbo and 500bhp with a lighter front than the R series engines.
Someone stop me from thinking these things - pleeeaaaaase