You can also buy some used parts and building your own package.
If I was you with the sport seats, I would buy the modules, buttons and making my own harness.
I can sell you 2 modules + seat harnesses for non-powered / passenger-powered and this guy is selling the driver-powered with memory
I saw a few times the buttons on sale on e90post and ebay.
The programming can be done by yourself by adding the option to your VO (see the programming section on e90post)