Vipermann,
While I did not install a cd changer with my RB1 I did install a Dodge/Chrysler Sirius unit. The reason I chose to go that way was the dealer had a unit for another Chrysler product in stock and let me buy it with the caveat that if it did not work I could return it. It came with the correct wiring and plug for the RB1 interface and I just adapted it for the Viper.
IMHO I would see what cd changer a dealer has in stock, open it up and determine if it's what you want. If it is, you can always pack it back up and search the internet for the same p/n if you want to competitively shop.
Also IHMO, I believe unless you are willing to give up some cabin area, the trunk mount may be the only option. Just make sure the cable that fits in the back of the RB1 is long enough to make it there. The kit I used was from a PT because this was the only in stock item the dealer had and the price was very good. Suffice to say the cable length was if anything too long! I ended up giving up the rear center console section for the Sirius box. I really had plenty of cable!!!LOL
I hope this helps in your decision.
Larry