it's not cost effective to put turbo's on the VG. It's cheaper to just swap motors for one with TT's.
but to answer the question, yes I suppose it could be done. You would need to route oil lines for the turbos, new injectors, new internals, lower compression ratio, new ECU, turbo's (of course

)
i probably left something out so just read this:
http://www.twinturbo.net/ttnet....html