I picked up a used 85 Miyata 1000 with some swapped crappy wheels.

I have some road hubs laying around that are spaced correctly for the frame (126 & 100). The front is a shimano 600, and the rear is a shimano 36h 7 speed hyperglide. Both are 36h.

Can if build these up with a touring rim? Or would I be better going with MTB hubs?

There have been many thousands of fully loaded touring miles logged on 126mm rear hubs.

yep me too. 126mm / 36 hole suntour sealed hubs with wide araya rims.

+1 re Doug. And FWIW, the next step in progression is to consider 130mm road hubs rather than 135 mtn hubs. Your frame can easily accomodate 130mm hubs. 135s will probably require cold seting and dropout alignment.

I've ran 600,now 105 hubs for 34 years,no problems.

I cracked a 600 rear hub in half many years ago but that was not the hubs fault.It was a freewheel hub and the axle bent so much the hub couldn't take anymore.That was before I knew about bending freewheel axles on touring bikes.

As has been said,a 130 hub will fit in there,no problem,so you have more choices.

I had perfect service from my 126 wide Phil rear hub for freewheels, for 20 years.

the unbendable axle and sealed bearings are the feature..