2002 jimmy factory headunit replacment

I know I probably typed some things I should'ed of by what the forums rule say.But its hard finding the right words for a topic,So Im sorry

Now my Question

I Have a 2002 Jimmy SLS I just got 1 week ago,Its time to replace some things but the info i know seems to be wrong with what other people have to say.Have never worked on a new jimmy before.

1,Was under the understanding that all 2000 + Gm cars were on the Data-bus 2 system,So you had to buy a interface module to keep the RAP feat and some other safety feats to 100% install a new Headunit correctly.(or loose the chimes,RAP by just taping into the acc wire)

Now I just read this and this guy is saying you don't need a interface module and they don't make a DD mounting kit for are SUV'S

http://www.zr2usa.com/mboard/index.php?showtopic=7322

Well Looking in my Metra 2006 catalogue(haven't gotten my 07 one yet keep telling me june or july)says part #99-2003 for a D-Din mounting kit

But then when I go to Crutchfield.com and do 2001 Jimmyf(don't have 2002) It says the Double Din radios won't fit and Gives me this radio Harness.

http://www.crutchfield.com/S-oXLjMko1tA7/cgi-bin/ProdView.asp?g=103000&I=120701858

I nee d to find out

1,Can I install a Double Din radio in my 2002 Jimmy

2,Do they make Double Din mounting Kit(like metra says they do)

3,What wireing harness do I use(will it keep my RAP feat)

4,What antenna adaptor do I need

Really I don't need the GMRC-01 like I used In my Cavailer

So Does that 70-2003 harness supply a switched 12v like the pre 2000 harness'es do??? or those interfaces do

This is,the 70-2003 harness right

http://www.audio-discounters.com/70-2003.html

Now with the RAP feat on this truck,it lets me roll the windows down etc,Unlike my 2001 Cavy that even when I had the stock radio it only keeped the radio on for 10 mins unlike 20 mins with the jimmy