Pretty much anything that can get up to 400 degrees will work, and they even make infrared heating lamps for those really large pieces that wont fit in an oven. It was my intention originally to keep my old oven and use it for curing back when we bought a new one for the house but I decided not to use it since it was gas and I also didn't want to give up the garage space for it at the time.
My friend's oven setup is just an old refrigerator he gutted out and lined with rock wool, then he bought a heating element kit for a ceramic kiln off ebay for like $20 and installed an automatic timer on it. His will heat up to 400 degrees in like 5 minutes and it's big enough to fit a full size Harley frame inside, I think he has maybe about $200 invested in that one and he built another one the same way but it's set up to heat up to 1200+ for ceramic coating exhaust pipes and headers etc. I'd like to build both types for my shop since there is a good profit involved in doing this and I can offer the services online or locally to help keep the money coming in during the slow season.