Adding A/C and heat

[ryans69chevy]

Getting close to redo my cab. I'm going to fix all the rust and I want a clean looking firewall. I live in ND so I'm only going to drive this pickup in the spring summer and fall. I'm not sure how much I'd actually use the a/c. I actually think I might use the defog more like if it was raining or if it was a little chilly out.

My cab is a non a/c cab, only had heat. I'm wondering if it's worth adding a/c. If I would it would probably be something like what vintage air sells. I've checked out their website and it looks like they offer an additional kit for heat. Is anybody familiar with this? I'm more than willing to cut all the holes in the dash for a/c if need be.

Basically what I want is to get rid of the heater box in the engine bay. So I will do what most of you are doing which is "shaving" all the holes behind the box. Then with a VA kit I see something like 4 hoses running from engine bay into cab which looks pretty clean. Is it even possible to get a heater installed again if I shave all those holes? I don't know much about HVAC. Do a lot of people that live in my climate that have a/c actually use it?

Let me know your suggestions/advise.