http://www.autotoys.com/ has the SWI-X much cheaper. I actually just got mine this very morning.

Also, if you need a fascia adapter, wiring harness adapter, and antenna adapter, there is a fellow in the UK that sells them for 30 pounds. (about $50 with shipping)
The fascia adapter is available from other places, and possibly the wiring harness (though I hear it isn't as complete).
But the antenna adapter is a hard to find item. But thats assuming you have a tuner. I was an optimist and went ahead and got it.

PM me for more info, or go over to www.mini2.com forums and do a search for mikeythemini
Mini2 also has a lot of good info on how to take out the stock head unit. It is surprisingly easy. And the Empeg looks to be good fit.

Now just need the rest of the stuff to start the install.....