I have a Mc Xpress silverbox for the secondarys injectors. Works good, took a few hours to set it, but now it is ok up to 1,4 Bar ( 20 PSI )
Did it on the street - looking at Boost, Rpm and A/F gauge the same time - then set the injector timing on a Lap Top.
I choose the 4 in 1 Exhaust - it is also from Mc xpress, I made a Db eater in the outlet - only a short straight Tube - because of the Laws over here.