Also Paul, although I could be proved wrong (so I'll post it publically!!) you will probably have to do this in 2 stages, 1) get the exhaust and 2) get the engine done.
It would probably be a bit of a waste of upgrage funds to just take it in to someone to do it all turnkey.
So, again sticking my neck out here, you will need a 3-2-1 exhaust, probably by powerspeed as they have the drawings for a K series SV (they took them from Paul Allen's car a few years back) so you should be able to order one, and go and get it fitted when it's made. I doubt if there will be a better solution, and it is the absolute first step required for any upgrade.
So you can get that sorted pretty quickly!