Painless Wiring Harness Question

[77GMCTruck]

I'm wanting to change out the old tired wiring system in my truck. I was wondering which of the following would be best suited for it. It is a 77 GMC Sierra Classic with cruise control and manual windows and locks. I would prefer not to have to pay the $550 for the universal harness if one of the 18 circuit harnesses will work. Obviously I need the one with A/C, especially here in the south.

Here's the link from Summit Racing comparing 3 of the harnesses:

http://store.summitracing.com/compar...=KeywordSearch

As always your help is greatly appreciated.

Just found out the link does not work...

Here they are separately:

http://store.summitracing.com/partde...5&autoview=sku

Or

http://store.summitracing.com/partde...5&autoview=sku

Sorry didn't check the link after posting.