I decided to order a Gates Water Pump from Amazon...
 

[Edit: I am not sure how this ended up in DIY Guides, mods please move. Or I guess I can take some pictures and make a DIY out of it to add to the existing great guidance on here already :) ]

I have used Gates in the past and from the description it was unclear as to whether it had a metal or composite impeller. It came yesterday and it is metal. It comes with a non-metal gasket as well, that was broken, and there were tool marks and dings on the mounting face of pump. When I rotated it, there was quite a bit of resistance (I understand this is normal) but I could also feel a slight clicking or kind of a movement, it is hard to describe. So it is going back today. It was an interesting experiment.. and I guess the result was as expected. (We used a gates when we did the timing belt/WP change on my son's Miata and the experience was different, it was all good, maybe they use different vendors/manufacturers to make the actual pieces)?

So I ordered a Pierburg water pump from p a r t s g e e k . c o m for $225.23 with free shipping, that is the best deal I found on that pump by a decent amount.

I had already ordered the WP Gasket and Wahler low temp thermostat and gasket from Pelican and that came in yesterday as well.

I was going to do WP/UD Pulley/ Low Temp thermostat over Thanksgiving but now it is moved to Christmas break :)

Moral of the story - I knew better but wanted to find out for myself anyway :)

The pierburg water pump came in and it is a work of art. The pulley is silky smooth with consistent resistance, the machining is very nice, and the impeller is composite.

I hope to install it this weekend and will update this thread since I accidentally put it in the DIY thread, I will see if I can find something to add of value.

Make sure to order a new OE Porsche water pump soon. You're going to need it. Sorry. But true.

Uggg I was hoping the pierburg was one of the good ones. I am not sure if I can send it back so I may have to take my chances. :eek:

Edit:
I got my recommendation from this thread (the whole thread is good but is one of those semi-hot threads with discussion about low temp thermostat)
http://986forum.com/forums/414204-post11.html

And from here (pierburg is the one included when you buy the WP bundle from Pelican)
http://www.101projects.com/Boxster/Projects/034/parts.htm