I have a couple of them sinks here. All I used was a removeable 3-4 gallons water container under the counter. Easy to switch over and most importantly to me....keep clean.Too many years at sea, having a hard time trusting anything out of a tank.
And then at first had an electric pump but switched that to a hand pump,simpler and just as effective for my needs.
I see your oven now, they all suffer from the same problem, the heat deflector plate is too thin, may warp even more if you crank up the heat. Then the pizza will not cook evenly. Or pies or.....whatever.
1/4" steel plate bolted on the bottom without plugging the holes....look around at the dump if they let you, that's where I find that kind of stuff and sometimes even "almost" running motorcycles.