If you have any type of outdoor stove or burner, you can use it outside. We do have a tava stand https://www.desiclik.com/stainless-steel-tawa-stand-for-restaurants-24084.html which is typically used to keep the tawa warm with a buffet burner but not good enough for cooking.
The tawa stand is sold separately, you can search for product id 24084 or use the following link - https://www.desiclik.com/stainless-steel-tawa-stand-for-restaurants-24084.html
We do not have a tawa that is 6" deep in the center - they are mostly 1" deep from edge to center. 20" Tawa is currently not available and will be in stock in about 4 weeks. This tawa is around 4mm thick.
make sure to measure the diameter of the burner and if you have room to place 16" tawa. Typically, u can use on a 12" burner if you have enough room to place the tawa.
20" tawa without handles is sold out, with have this tawa with handles - https://www.desiclik.com/large-tawa-w-handle-iron-roti-pav-bhaji-tava-21946.html