I've been with Sirius for about a year now. Knowing that XM was gonna lose the Nascar qualifying and the races themselves made it an easy choice [Sirius vs XM] for me.
I tried several of the Sirius receivers in my vehicle, and finally setled on the cheapest model they have. I believe its called the Sirius One, its the one unit they have that looks ALOT like a radar detector. It sounded noticeably better than all of the other models I had tried. I bought it at Radio Shack for 29.99. It came with everything I need to install it into my Ford Escape SUV.
The Sirius One does NOT have a home kit available, but its very easy to buy the required power supply and antenna at Radio Shack, and then use the unit insides to broadcast Sirius to any FM radio you have laying around.
Also .. one thing I learned is that having the antenna installed on your roof of your vehicle - like it's supposed to be - makes a world of difference!! I had my antenna just laying up on the dashboard for quite some time and had drop offs sometimes. I finally took the time to do it right - with my wifes help - and the reception is 99.99% perfect all the time.