Not sure exactly what sports seat you're looking at, but the sports seats in my Boxster (2004 Anniversary Ed.) are heated. It's a common option for that model, as the sports seats were standard. I don't think many regular 986s opted for the sports seats. Oh, and the seat bottoms and backs are both heated.
By the way, I hate the sports seats and would swap even with somebody if it weren't for the fact that mine are Cocoa Brown and the only way that color was offered on 986 was the Anniversary, all of which had sports seats. I hate how the shoulder bolsters pinch my shoulders forward; after a short time I feel like I need to get out of the car and throw my shoulders back to keep from collapsing in on myself. The bolsters, rather than wrapping around your midsection like a good sports seat should, flare out up at shoulder height, and it's not so comfortable. FWIW, I'm 6', 180 pounds, fairly normal build.
Matt
Here's a
bad picture of my seats, but you can see the big shoulder bolsters.