I'm biased obviously since I did purchase MMP Stage 3s. I believe they will no longer be selling the Stage 3s, just the 1Ks or their coming stage 2s. I'd think you'd want to lump the choices a bit more separate:
MMP 1Ks
VTT GCs
Pure Hi-Flo
RB EVOs (I think that's the biggest ones)
Frankenturbo
VTT GC Lite or Stage 2+
Pure DD
MMP coming Stage 2
RB Stealths?
For your power goals, I'd suggest the first bunch. This is purely my own observations, so take them with a grain of salt.
MMP 1K - lot of people with them, still installing, yet to post dyno numbers. Likely to be in the same vicinity as MMP Stage 3 since most people aren't building motors and thumping 30+ PSI.
VTT GCs - new redesigned 2.0s are supposed to fix the turbine wheel issues the older models had. Those that have GCs seem to love them, good power. I would consider them. I did like the older ones with stainless housings over the cast iron, but that's me.
Pure HI-Flo - I don't know the full specs no Pures, but I think these are probably a TD04-19T like most of the others. 650+ whp. I don't think I've seen a negative thing posted about Pure ever.
RB EVOs - I dont know RB's naming convention, it's either the EVO, or Super Evo or something like that. I've not seen anyone as of late posting anything about them, only threads from 4 or 5 years ago. They are good performers and are on par with the others. RB had a smoking issue a few years back, but that seems to be resolved (then again, if no one is using them, is there still an issue, or has no one just run across it.)
For your goals, I think the stage 2/stealths/frankenturbos might be pushed a bit too hard. I'd want to stay with a TD04 CHRA as well.