Having had one of the first Twin Turbo rb25’s in Australia, Queensland atleast it’s not really worth it.
What’s the goal for the car? Street? Drag? Drift?
Rb20’s aren’t really ideal straight out of the box as well; do you plain on running a stroker of any form? Cost Vs cost it's cheaper, easier and a better out come to just upgrade to a bigger single + support gear.
But hey, if you wana be a bit different, why not, one of the guys on Secret drift had a Twin Turbo rb20 in his Laurel, was meant to be pretty responsive, only made about 220rwkw though I believe..