Conventional Jeep trucks and wagons from that era are "Utility Trucks" and "Utility Wagons." There were also forward control trucks, "FCs."
Yep, Jeepforum does not cover them. Is it a Utility or a FC?
I guess the site with the most traffic re these trucks would be Willystech http://mvpimages.net/willys/show.htm
- but they have a mailing list format, not a forum like here.
Can't help you with the PS conversion, without knowing whether it's a FC or a Utility.
The brake question is easy if you want to keep your existing axles. Disk conversion is the same for all the Jeep closed-knuckle front axles. You can do this using junk yard parts. Check out the JP article http://mvpimages.net/willys/show.htm
- there are lots of other resources on the internet if you search. If you have questions, I suggest you ask where there are lots of owners of old Jeeps with closed-knuckle front axles, like Willystech or earlyCJ5.