Which PS setup to use

[bw4sale]

I'm trying to add power steering to my '68 and I need advice on what set up to look for. I've already got my steering box mounted. It's from a '69 GMC. I have a 68-72 pump and lower bracket, but I don't know if the pump is any good and I don't have the upper bracket. My motor is out of a '79 truck. I also just realized that my block is not drilled for PS brackets. Suck! So, should I look for a 68-72 upper bracket somewhere or should I try to find a later model bracket and pump set up? Also, I'm assuming I can just drill and tap my block for the PS brackets? Thanks.