GT30R or GT35R then!
This was said in jest. Those are big HP turbos for small engines.
Your best bet (IMHO) is going to be a Low Pressure Turbo (LPT) from a Volvo V70 MY 2000-2003
These run on 2.4L 5-Cyl engines.
The problem you're facing with low boost on a 3.0L engine is most turbos
are sized for smaller displacement engines.
1.3-1.6L - Small
1.8-2.0L - Medium
2.2-2.6L - Large
VQ30 TT = 2X - Small Turbo
B5244T = 1X - Lrg. LPT
You're going to have A LOT of exhaust flow, so too small of a single turbo and you'll over boost.
The Volvo LPT is small-ish, but designed to work on a 2.4L engine. Those engines boost about 8 PSI.
You'll probably need to enlarge the wastegate port a bit to keep from spiking your boost.
One thing that just popped into my head, run a single VQ30 TT turbo off of one bank of the exhaust.
Presumably, that would halve your boost pressure.
You will probably want to run a boost referenced fuel pressure regulator
Capt. Delinquent Racing
The One & Only Taurus V8 SHO #31(now moved on to another OG Delinquent)
'17 Vodden the Hell - (No) Hope for the Future Award, '08 AMP Survivor, '08 ARSE-FREEZE-APALOOZA Mega-Cheater