DIY is the way to go with these water pumps. Don't expect original Porsche to last long either.
Water pump on the way out?
Except for the PITA of dealing with coolant, the actual WP change is relatively easy. All bolts except for one can actually be reached with a torque wrench, too.
I invested in the Airlift vacuum system; well worth the bucks IMHO. My compressor is only 4 gallon (they say you need a 10 minimum) and works perfectly. I've heard of others that have even smaller ones and it's worked ok too.