I use a Toko ski iron. Most of the ski brands use the same model, but change the color and the printed logo. As long as you can adjust the precise temperature, and if it's flat with no holes, you're good. Of course, a generic clothes iron will do the job, but you can't adjust the temp as well, which makes it tedious for waxing, since you usually want a precise temperature depending on which wax you want to use! Colder waxes= higher temp, Warmer waxes= lower temp.
If you have any questions regarding waxing, don't hesitate to ask!