Kit to install readily available PS pump on a 67 small block

Not a kit, but-
On late A bodies (and maybe F/M/Js, too?) they mounted the PS pumps higher up on the engine to clear a low mounted air pump. That setup is on my all original '75 Swinger. It should give you the water pump inlet clearance that you need, but I have never personally tried this on an early iron water pump.
The big issue is that in order to get clearance for the rear fittings of the Saginaw pump, they have to push it forward, aggravating an already substantial pulley depth difference between the iron and aluminum pumps. Chrysler drove the PS pump in this case off the front of a 4 groove crank pulley, which is quite a distance for you to make up on your early engine.
Borgeson makes a simplified pump bracket for the Saginaw pump, but it appears to be engineered for the late motors, but I can't tell for sure. On a positive note, they sell special banjo fittings for the rear of the pump to help alleviate some of the clearance issues with the pressure lines, so maybe you can come up with something- a little of this, a little of that, shim this, shave that...
Good luck!