OK, I may be able to help 'cause I've been knee deep in OEM radios and their model numbers for a few days now (trying to upgrade my Business cassette deck to OEM MP3 CD)...
If your car is a 2000, it will almost positively have 2 antenna connectors on the back. If it is cassette, it will be an Alpine. If CD without the MODE button
, 90% sure it will be Blaupunkt. It would be worthwhile to pop the radio out for a minute and confirm this, as well as write down details from your current HU. Radio removal is an absolute piece of cake if you have the correct tool to remove the trim.
Now to answer your question - the head unit you will need has to have the MODE button and be a certain age or newer (I believe build date 09/2002 or newer). Then the XM interface you are looking at will work correctly, BUT the newer HUs have a single AM/FM antenna connector and a different antenna amplifier in the back of the car (at the c-pillar). You will need the antenna adapter for sure to convert the connector at the back of the new radio (you end up only using one of the antenna cables with the new radio), plus your reception will reduce somewhat unless you replace the amp in the back as well (which is expensive and not totally necessary unless you need strong FM reception where you are). The adapter cable P/N is 61 12 6 913 955 - here in canada they quoted me around $55CDN, I've heard it is more like $20US or so from Pacific or Crevier.
BTW, the newer head units have a number of nice minor feature upgrades, plus it doesn't hurt the SQ that they are made by Alpine.
Sorry for the long post but that is what you are up against. It isn't as bad as it sounds though.