Adding Sirius and Amplifier in 06 Prius

Just bought an 06 Prius (package 4, no Nav, no JBL) and I would like to
install an Kenwood Sirius KTC-SR901 Satellite Tuner & antenna
I have leftover from my previous vehicle. I would like to use the factory head unit to maintain steering wheel controls and interaction with the MFD. Without buying the SiriusPrius packagefrom Factory Interactive (because I already have the tuner) is there any way to achieve this?
I definately want the Satellite info (artist, song, channel, etc.) to be displayed on the MFD. Anyone know of any way to do this?
I've looked at the Blitzsafe & Soundgate interfaces, but they appear to limit what data can get displayed on the MFD. I've also considered getting the Solara Sirius tuner, but I've heard differing stories on how well that works in the '06.
To complicate things, I plan on adding an amplifier and would very much like to find a way to get line-level (RCA-type) output from the factory head unit (as well as an amp turn on lead) to feed to my amp. Any examples of line-level adaptors
that work??
Thanks in advance for any advice....