A SSR would be a good choice for this application since space is an issue. Crydom is good, AC/DC control with high amp output available. A Crydom A1225 has AC control, 25 Amp output, and costs between 30 and 40 bucks. When you install it, put heatsink compound between the relay and the metal backplate or box or it may not last long. Properly installed, a SSR is a great spacesaver.
