08 TahoeNav and Backup Camera Questions

howdy!
 
 I have been reading this forum for the past 4 days trying to get some ideas on how to install a oem Nav and backup camera into my wife's 08 tahoe.  It is a 1lt with out bose but has everything else.  After reading many many pages from everyone I wanted to post and see if I have come up with the right idea!
 
I know i need to get a 08 nav unit and will need to purchas the oem camera (well i guess not the oem but i need a camera).  After this it get a little fuzzy.  I saw lots of people talking about the lockpick and the JPcustoms harness.  I am thinking that i will get the GMX320 lockpick.  Do i still need the JPcustoms harness?  What about the voice rec.  Hows does that tie in?  Or in a 08 does it just work? 
 
Thanks for the help and any suggestions are welcome!!

I made up a couple of my install documents some time ago on how I did mine. I will post the links here but you are on your own installing these. These docs are what I did and your situation may be different, so use these as a guide and ask for help in the forums if something goes wrong!

Kenwood camera install - http://home.earthlink.net/%7Egenestoy/kenwood/camera_install.doc
Nav unit install - http://home.earthlink.net/%7Egenestoy/kenwood/nav.doc

Gene,
  Thanks for the doc's they helped a ton!!  Couple questions for you.  What JP harness did you buy?  I see one for a nav kit is that the one?  Also why do you need to hook wires between the onstar box and the Nav unit?
 
Thanks!!

Here is the JP kit - http://www.jpcustoms.com/store/customer/product.php?productid=17812&cat=359&page=1
looks like they may have changed it a bit from when I got mine, but same price. The connection to the Onstar box has something to do with the voice recognition I think which works perfect in mine. Be sure to ask JP about hooking to the Onstar box as I heard they are not including that connector wiring?

Ok so I think I have everything figured out except now I talked to someone at JP Customs and they informed me that the NAV radio will not power my speakers since I am a non bose tahoe.  He said that I will need to add a amp to the mix with a adapter they supply to get enought power to my speakers.  Does this sound correct to people?  If so has anyone done this and had sucess with any amp?  I am thinking a 4ch 40watt amp should work well.  Does anyone have any other suggestions.