RB30E - same as the other models.. and same as VL non-turbo.
Well Silhouette does come with LSD so that should help, only problem is that when it blows - not the easiest thing to get a replacement for, or cheapest.
Depends where you start from.. This is what I paid..
VLT Injectors: $120
VLT ECU: $120
VLT crossover: $60
VLT Manifold: $200
Never really got the turbo, I was going to use an RB25det turbo I had - ~$400ish (about same for stock VL turbo). Another few hundred for a dump pipe to be made, and turbo lines. Up around the $1500 mark probably by the end to go for turbo.
If it's an auto.. budget another $1000 for a manual conversion, as the gearbox won't hold for any significant length of time.
In the end, for me it just wasn't worth it (and I swapped up for the import for barely any more - fairly special deal though)
but anywhere from $1500-$2500 can get you into turbo land... RB30ET is a nice combination though.