Boiler for bamboo steamers?

Due to the limited size of my truck, 11ft x 7ft work area, I decided to go with a dumpling truck versus sandwiches. I want to be a bit different and I have some great recipes. This decision also allows me to go without the refrigerated sandwich prep station, grill/griddle and exhaust vent and I can fit a bigger commercial refrigerator on board.
 
Now I have to figure out a nice steamer setup for the dumplings. I am going to use the standard stack able bamboo steamers but these are usually used over a pot of boiling water which I do not want to use.
 
I do not want to have burners with pots of boiling water on board, I would like to have a steam table setup that the bamboo steamers can fit on but I cannot find anything like this online.
 
So before I look into design and fabrication, any ideas?

Could you cut a round hole into a rectangular cover?

I thought about that and I am looking into the dimensions of available steamer trays and tables. Also, I decided top go with stainless steel versus bamboo due to health standards. Thanks for your input.
 
I was looking for an out of the box setup but I am not seeing anything except for weird units on Chinese web sites.

Found something. taiko-enterprises.com/steamer.html

Just found something even better.
 

There you go.

I committed to buy on Ebay before I inquired about shipping. I offered the seller 300 and they accepted but shipping is 398. So needless to say, I cancelled this purchase.