So I have a built bottom end GSR motor in my EK Hatch. I recently starting auto crossing it and while it has been great, I'm looking for a new turbo with quick spool to replace whats in there. Currently I have an eBay variety 50 or 57trim (never measured and I wouldn't trust there measurements), and its doing alright, no smoking or shaft play (I know ticking time bomb). Anyways it made 309whp on 16psi which seems pretty en efficient for a GSR, so I'm looking to swap to something else.

Motor Specs:
JDM GSR Block
Wiseco Pistons 8:6:1
Eagle Rods and ARP Bolts
ARP Head Studs
Stock head refreshed with new valve seals
4K miles

Spoolin Log Manifold and 2.5in 5 bolt DP
2.5in IC Piping and Mishimoto IC

I'm thinking of switching to a 3in and V band so I'm not dead set n the new one being a drop in. Ideas and insight welcome.