I would consider replacing with a universal set-up from one of the companies making such kits. You buy a box with heater, and a spa-side control panel. You choose it by the number and voltage of the pumps, and other accessories. Many of these boxes can switch from 110 to 220, including switching the motors, blowers and even ozone from 110 to 220.
Spa Depot has them, and about a dozen other spa parts retailers.