I like the Alpine, Pioneer, Eclipse, and Kenwood units.
I like the Pioneer AVIC-N2 since it included the navigation, plays mp3s, cds, dvds, etc..for under $1900
For Sirius you have to get a the Sirius Satellite Radio Tuner.
One thing about the AVIC-N2 is it has a gyroscope and other safety features that won't allow you do play with the navigation or play a dvd while the vehicle is in motion. I've *heard* (
) that these can be bypassed if you know what you are doing though (need to be able to solder as well).
Alpine is really nice as well but the flip out will run $1400+ (depending on which model you get). And then it's an additional $1000 or so for the navigation.
Kenwoods are nice as well. Never looked into adding navigation to one of them though....
Eclipse is nice since it will also include the navigation with some of the models. And it has two disc slots, one for the navigtation dvd and the other for whatever dvd/cd/mp3 you want to play (at least on some of models it's like that).
I think all the Sirius Satellite Tuners that you'd need for the different brands run $80-100 and as was mentioned will just plug into the head unit.
I am in no way recommending that anyone bypass any safety features since that would be highly illegal.....and may void parts of the warranty (or the entire thing).