Help with my Holy Grail

[Bad Jackson]

I'm sorta new & I don't own a truck... Yet. I need some help with prioritizing my list of characteristics of my perfect truck.
For me, the perfect truck is a:
1972 GMC LWB K10/K20
Factory A/C
Original Stereo (I don't want the dash cut)
Manual Trans
Metal Box floor
Minimal Rust
Survivor
Not Green
Good Condition
Reasonable Price

Obviously getting all these wants is a long shot. So, I was thinking of sacrificing a few things.
4X4 and Manual Trans, thinking those would be easier to change later.

Can anyone help with their options on this. Swapping the box would be easy too, but then I'd have to paint it.

Thanks.
Munsk