Suburban Vintage Air A/C

[MAC71]

I have installed a Vintage Air A/C Gen II sure fit A/C system in my 72 Suburban and it clearly does not have the capacity to cool and heat the inside of the truck. I am pondering going back to factory A/C, pulse adding rear air. For rear air I was thinking about instead of in the rear overhead, installing the A/C unit under the middle seat and running the A/C vents through the side panels. I really do not want to have to deal with 50 feet of A/C hose to reach the rear over head and I would also like rear heat.

Any one have any good ideas or thoughts?