Nick, if you want to know any specifics, PM me and I can try to answer or give you my number to have a chat.
It's not a cheap move...but a rewarding one.
A C2 is all you ever need on the road...the rest do it more often in all weathers, more readily, or more hardcore...but a C2 is a damn fine steer.
Living where I do, I'd suffer a slight lack of front end feedback in exchange for 4wd (I borrowed a 997 C2S and almost spun it, so used to the C4S, and the liberties you could take with a C4S + PSM...but then again, the 996 C4S is more than the sum of all the parts!) but no doubt the C2 is a purer machine.
Since you aren't afraid to admit the MK5 is a fine machine...you'll love it!
If you can fine a late-ish 3.6 with Vario Cam and Vario Ram, they are the pick of the 3.6 non GT3 NA engines...I have a modified airbos I'll send you!

It'll make you smile...