He said he wanted to go to a T3 housing, and the FP manifolds are mitsu flanged.
If you are trying to keep the cost down, have you considered the Turbonetics/Treadstone cast T3 manifolds? They are cast, so you shouldn't have to worry about cracking as much. The wastegate placement on those is often debated, but for someone looking to save some money, it's not a bad option.
http://www.treadstoneperformance.com...Turbo+Manifold
I can't speak for the megan because I've never used one. But the fact that they share the exact same design as the other cheapo ones on ebay that continuously fail would make me worry.