While CPE make some good gear I would go the following;
CPE FMIC (the one with the ram-air) - I think you are talking about the corksport one? The CPE doesnt have RAM air... This is a good bit of kit and if you have the moolah for it your heading in the right direction.
CPE Dump Pipe - I would contact chris from best mufflers in Sydney. His DP is great, and the cat is flanged for easy removal (Read, dont have to remove the whole DP to replace cat @6hrs labour).
CPE Cat Back - Nothing wrong there, though there are other options.
CPE Rear Engine mount - Win! Got one too, V happy.
MY16 WRX STi Crystal White Pearl
-= Rally Armour Flaps - 2XS Muffler Delete =-
FG FPV F6 MKII Vixen - SOLD
-= Bluepower SRI - ID1000 Injectors - Venom Cat - XCAL3 - ProcessWest Stg2 Intercooler - 359 RWKW=-
CX9 Grand Touring Stormy Blue
-= The rolling armchair =-
6 MPS Velocity Red - SOLD
-=Cat Back Exhaust - Pirelli PZero=-
3 MPS Aurora Blue - SOLD
-=PG SRI - PG Inlet - ETS TMIC - GFB Hybrid BOV - Best Mufflers DP - Eibach Pro - AccessPort STG2 - Autotech HPFP - ITV22 - Michelin PSS=-