A Porsche Boxster S isn't normally the first choice for an engine swap. Original Poster Escy has previous in this regard though, having performed a few engine swaps fitting 2ZZ engines into MR2 roadsters before looking at his next project - a VX220 fitted with a Saab B204 engine. However, VX220 prices increased and his eyes turned to the Boxster, which shares a bell housing pattern with Audi. It got him dreaming of 400hp+power from the Audi 2.7 bi-turbo V6.
Why bother seeking out a Boxster S as a donor when a 2.5 or 2.7 would seem a cheaper starting point? Well, the S has an extra radiator at the front, better brakes, six-speed gearbox, larger wheel bearings ... and those much feared IMS issues our OP didn't want to risk. If big bills were the worry you might question the idea of going to the bother of an engine transplant but why spoil the story by bringing logic into it! Predictably it wasn't as easy as it seemed either, the starter motor being on the wrong side meaning a need to swap to a 987 transaxle and a mix of 986 and 987 gearbox parts to make it fit. Coilovers were needed to make room for the driveshafts and a custom exhaust was fabricated to keep the standard centre fit look.
Quite the job - by now you'll likely be wanting to know more and join the thread for the full story!