Get your equipment from Salonserve.com. It's very good quality and you've got loads to choose from and best of all it's not overpriced. i paid £48 for a double wax heater. I get most of my consumables from them as well. Perron Rigot wax is the best. Takes a bit of getting used to as you think you need to use loads like other waxes but you don't so in the long term you get better results and works out cheaper for you.
I personally now use the Hive Digital heaters - 1000cc ones. I currently have two of them and one old style Analog heater. The Hive ones are, in my experience, the most reliable and consistent for maintaining a temperature. The digital ones are great because you set the temp and just leave them. The only problem with them is that you cannot use them on a timer plug to warm the wax up before you arrive at the salon. if looking at Pot & Spatula I always recommend the 1000cc units as they will hold all tins and sizes of wax. For cartridge / roller waxing I also recommend Hive - the Multi-Pro unit is great - the little one with three slots at the front is the one I have. It fits both 80 and 100g cartridges - the toaster style that you drop the heaters into the top of only fits 80g cartridges.
Hi, try BaByliss Pro double wax heater, has two independent wax pots, you can use one for hot wax, one for warm wax, two individual switches on/off and 10 temperatures settings. I found it quite useful.