well being a XM ready HU, that means you can hook up a dedicated "hide-away"
tuner to your radio via a data bus port that can decode the xm radio.  The
advantage of having an XM ready radio is that you can view artist/track info
on your headunit's display as well as have a 100% clean digital signal.
With the pieces you are looking at those are more plug in play type items
and will be RF modulated.  RF modulated means you will be tuning your radio
to an FM frequency to listen to XM radio, unless your radio has an auxilary
input.  RF modulated systems will lose some sound quality, which is noticed
by some and not by others.  So you kinda have some pros and cons for the
whole situation and you have to decide.

I would suggest the alpine tua-t020xm to compliment your head unit. It
should plug right into your alpine and all you need is an antenna and a

XM itself is supposed to be releasing a universal tuner box that will work
with all brand head units. It is supposed to be out in August and retail for
about $99. Consequently virtually all the radio manufacturers have stopped
making the tuner boxes. You will find it very difficult to find an alpine or
pioneer tuner now. The XM produced unit undercuts the other manufacturers.

The Delphi and the XM commander are universal RF modulated units. I do
notice a significant sound quality improvement with my Alpine direct
connection vs. my wife's Pioneer RF modulated unit.