A lot of money for keeping the stock turbo.
I'm not familiar with their dyno (do you know what WRXs baseline at?), and I've never really heard of them in the Subaru world. Personally, I'd go with a more well-known shop, if it were me.
As for the mod list, I'd do things a little differently...
PW TMIC instead of the Perrin FMIC
DW fuel pump is fine
ID1000 injectors instead of the DW850s (I'm assuming this is so you can have both pump and E85 maps?)
Catted downpipe instead of catless (or consider EWG)
If you have a hatch, something other than the Q300 since a lot of hatch owners complain of droning (sedan owners don't)
Nice choice on the headers (wrapping or coating them?). I wouldn't bother with the uppipe unless going EWG
AEM or Cobb intake (with the airbox, if you go Cobb)
GS makes a good EBCS
Skip the fuel rails
Consider an aftermarket bypass valve (Forge makes a good unit that isn't too $$)
Some of that, I wouldn't even go with, if your plans were to retain the stock turbo and use pump gas.