Dont know much about 6boost probaly because I live in CAlgary, AB Canada but in NA we have full-race.com and there shit is unreal they have robotic tig welder and other stuff but this is their manifold they make it for the RB25 and 26 application.
Quoted form their website
The Full-Race Response Manifold designed for instant spool, optimized low end and midrange power delivery. Applying Twin-Scroll Divided-Pulse technology with long, robotically welded thick-wall runners, this manifold will offer increased turbine efficiency, allowing the turbo to spool up very early. Runner geometry is adjusted accordingly for the known tendency of RB engines to run slightly lean in cyl #6. It can fit any size T4 frame turbo from GT35R, GT4088R, GT42R and GT45R.
Key design features:
Constructed from thick wall stainless steel.
TIG welded for ultimate strength and reliability.
True merge collector creates a turbulent free area for the exhaust gasses to enter the turbine housing in even pulses at high velocities.
Flanged for (2) Tial 44mm wastegates only.
All mating surfaces machined flat for a leak free seal.
Application Notes
A/C compatible ONLY with the R33 and R34 A/C compressor and lines. Will not work with the R32 A/C system.
Also available for RB25det