New 1964 Dodge Dart GT Owner

I have owned my 64 GT for 8 months now, and I have done a lot of work to it. I am considering some future upgrades and I would like some suggestions on obtaining the right parts for a man on a budget.

My first upgrade would be converting my 225 slant 6 to power steering the car is a bear to steer at a dead stop. What parts do I need to do this?

My longer goal would be to convert to disc brakes, my one concern is keeping the 5x4 inch small bolt pattern in order to go on to my much longer goal of replacing the rearend with an 8 3/4. Can the bolt pattern be maintained on all 4 wheels? And will a set of 1971 small bolt rallye wheels fit now and after my upgrades?
Iwill trade power for your manual steering box