why?

A custom manufacturer should be able to produce whatever you need for the appliances. It should be a matter of having one tall unit with rework cutouts each for their designated appliance

Iwant two to speed up leftovers for large family. Dont want it on the counter. Dont want custom cab.

seems like something they would be able to accommodate in a wall oven tower cabinet. I would go to the kitchen desk at Home Depot and ask.

please be careful to not have these set too high - you loose strength in your arms when carrying something above shoulder height - so always make sure you microwave is lower than this height to lift heavy, hot things out of the microwave safer !! :-)