Thinking about a single tier

I purchased some Bayou Classic 82qt kettles and plan on putting some weldless fittings in them. I want the option of doing 5, 10, and 15.5 gallon brews. I'm going to modify 3 Bayou Classic SQ14's to make my brew stand (I already use one). My questions are:

1. Should I upgrade the burners to banjo burners, or just keep the ones that they come with?
2. Using one of the kettles as a mash tun is what I am planning, will this hold the heat well? I live in San Diego and the weather is perfect 90% of the time. What is snow?
3. Any other thoughts or suggestions?

I have all the burners and like the Bayou Classic KAB4, if you are using the jet burner now and it's working great. I use the jet burner for the HLT and MLT but I like the bigger burner for the BK. The pot is not what keeps the temp as much as the thermal mass of 15gall of wort in the MLT. I brew in cold-ass Chicago and still only loose 3or4 degrees. Don't wait too long before making the single tier, it makes brewing so much nicer. Also Chuggar is having a sale on pumps now, FYI.