My humble opinion on Gen 2 options:
- PASM, don't rate it - you're better off with revised suspension (caveat: I haven't experienced that DSC mod)
- sports seats - nice to have but the standard seats are fine
- larger 19" wheels - yes probably a must have but they do give a firmer ride than 18" of course
- sun roof - I hate them with a passion!
- Bose - not worth the money, simply because you'll want to hear the engine/exhaust
- Sports Design wheel - yes a must have for me, you really don't need multifunction controls
- universal interface thingy - dunno really, I just want radio, and my iPod, don't care about Bluetooth etc. but that's just me. I navigate using an obsolete thing known as a paper map
- Sports Chrono - must have with PDK, can't see the point with manual
- cruise control - never use it
- heated seats - never use them, if it's cold I'm wearing a coat anyway
- PSE - not great on a Gen 2, you need a proper aftermarket exhaust system
There's much to be said for a bone stock 3.6 Carerra 2 that you tweak to suit your own tastes; it's what I did. Disclaimer: all of the above is my opinion and should not be relied upon by third parties. Other opinions are available, please read T&C's, UK only, over 18's only, subject to status.