just go to the forums sponsor sites (mvpmotorsports.com, WOTM.com....etc) or the for sale section in the forums for a greddy 3 row. I saw a brand new one the other day. Yes it will bolt right up to the stock twins and yes you can weld on a BOV.
I think you need to be careful with Greddy part numbers....from the research I've done, there appears to be a 3-row kit with piping for the stock twins, and a different 3-row kit with piping for their single turbo upgrade kit. Both appear to have the same core assembly, power steering cooler relocation hardware, and coolant overflow bottle.
Part #12010026 (from Greddy website) is for use with the Greddy turbo.
Part #12010409 (from MVP.com) is for use with the stock twins.
Intercooler core for both is the 23R, but piping may be different. Maybe someone else knows first-hand whether this is truly the case.