Im wondering if anyone might have a clue what it will cost to replace the high and low pressure lines going to the rear evaporator?

Or can they be soldered together? They are both cracked at the fittings when changing the evaporator.

I got both for my 97 suburban from Rock Auto .com for about one third the dealer cost . They have great shipping also . Repair kits are to be had , but from what I understand go with new lines . They still cost some bucks , but it is worth it .

find a shop that welds aluminum

I just paid $1500 bucks for both rear a/c lines and the evaporator. Most of that was labor. The shop just shot gunned it, but my a/c works and i didn't have time to do it my self. I was throwing in 2 or 3 pounds of freon in it every time i needed the a/c for the last 2 years. If it lasts another ten years then it will have been money well spent.

Check this place out.
http://www.autoaironline.com/index.html

and this one, helpful folks.
http://acsource.net/acforum/