Youll want MoSi2 heating elements; 4 or more.
Its not just about surface temp on them, its 'energy' filling the chamber. Youll want a good power supply. The easiest way for a company to save money is using smaller transformers, so be aware. I wouldnt consider anything under 3000 watt.
Low cost will be Chinese ovens.
@rc75 or Dominion Milling would be a good start.
You can spend more, just make sure youre getting more. I like Mihm Vogt. There are others that are well reviewed. Nabertherm is one.
Factor replacement elements into the equation. Check with
@Dental Furnace Elements on availability and cost.