Thanks LAN for your confidence. This build is scary for me as I don't have prior build experience - more learning as I go so I'm trying to make careful decisions.
As I understand your EM systems, they are piggy-back?
So far, I think the Hydra is my best choice not just because its proven that it will communicate well with the SVX but also believe it provides the most tuning options that I know of in a stand-alone system - "end all be all" as some STI guys call it. Having an engineering background makes me want to know the status and have the ability to control the ECU. I think the Hydra will satisfy that. The price is heavy but I take comfort in knowing my STI friends don't get it any cheaper.