I have basically the same fryer, without the built in drain. I got mine from a Meijer store for a great price on clearance. I thouth about using the rectangle, but figured there would be too much evaporation, and it would be hard to manage the width when dumping the hot wort. So I purchased the biggest round kettle that I could find that would "fit", and saved the rectangle in case I want to fry something.
It took a bit to find a round kettle that would fit porperly because the side frame is designed in such a way that it sticks up about an inch all the way around the rectangle kettle to hold it in place. That extra lip made it necessary to find a kettle that would fit exactally inside the frame. Luckily, the round fryer kit that bass pro sells, without the burner, had an alluminum kettle that fit perfectly.
I looked at the Bass Pro model when I was there getting the round kettle. I would not trust the built in faucet for anything other than leaking. It did not seem to be of a very high quality, and did not have the smoothness of a ball valve (it looks like a garden hose hookup).
The little side tables are a nice place to put your beer down, hold a thermometor, etc.
If I had to do it again, I would have simply purchased the round fryer from somewhere.