After spending countless hours on my project of building a GMRS repeater out of two Motorola Mitrek Radios, I gave up and decided to buy a used repeater off of Ebay all tuned up and ready to roll. The reasons for the decision is 1st off, alot of frusteration trying to get two mobile radios to act as a repeater. The 2nd is I simply do not have all of the tools needed to tune up these radios properly, not to mention all of the problems with hooking them up together and the desense and reciever overload and ... the list of problems I have ran into is rather long.

Long story short, I got a deal on Ebay, $210 for a Uniden ARU-251 UHF repeater. The previous owner was also a ham and tuned it up on GMRS repeater freq:
Recieve = 467.625
Transmit = 462.625
PL Tone = 141.3
Its crystaled, tuned, and ready to roll. It will run off of 110V AC power or 12V DC power.
You can view some info about the repeater here I downloaded a copy of the manual from there.
There is some addtional info on it, including:
http://www.qsl.net/w4xe/new_page_1.htm
http://www.repeater-builder.com/uniden/uniden-index.html
http://www.eham.net/reviews/detail/6073

For Motorola T7200 users, here is what you need to have set on your radio to access the repeater:
Repeater channel 18, Code 22

If I had one piece of advice for someone that was looking to build your own repeter with limited knowledge like myself, DON'T! I will admit I learned alot, but I also went through alot of frusteration and unless you want to learn how the radios work, inside and out, I reccomend getting a repeater off of Ebay or something similar. Its just not worth the trouble
The repeater will be putting out 15 watts from my house and my GMRS call sign is WQDX973