Yes you can do ir. It is a lot of work and do not start if you don't have the time to learn and do the work. No one is available to finish a half done project.
12 volt conversion(lots of ways, here's one)
12 volt denso mini one wire alternator $100, ,Battery $100,voltage dropping diodes for gauges$10 ,replace all bulbs $80,Overdrive conversion (you will get a world of different opinions, this is how I did it) Convert solenoid to 12 volts using 56 or later coil and body and 6 volt plunger, new 12 volt relay $10.
A.C.
I include photos of an actual A.C installation on a 4 cyl. HJ.
You will have to fabricate you own A.C. bracket, none are available.
The A.C. compressor goes where the generator used to be and the alternator mounts on a bracket secured to the head
The Cooling unit mounts in the trunk with the vents coming through the package shelf.
I can not give you details as I have nt made an A.C. conversion myself, to much work.