You can tell them that Alex from dent sport referred you if you like. The prices are very good and the turbos are developed with help from MHI. The turbine housings allow for a direct bolt on. The HX35 is the updated equivalent of the MHI 20G turbo and robust enough to handle anti-lag.
The other, more expensive option is something from ATPturbo.com in the form of a GT3071R Garrett BB turbo. I have one on my car but it has yet to run so I can't attest to it's power. It's good for about 400whp on AWD.
They are widely used here in the US for builds. They're hard to reach sometimes but the quality is unmatched. We have an engine from them at the shop now built for 700hp and it should be ready to produce by the end of the summer.
I am more than willing to help you and I'm trying to set up vendor status but no luck on replies. I'm not benefiting from these references so mods, please don't delete my post.