Quickest way to steup up to 15 gallons

[guinsu]

I hate posting really open ended questions but I am stuck figuring out all of my options. Basically I am in the process of opening a nano-brewery but in the mean time I am showcasing corny kegs of my beer at events to get the word out. Now I might have an opportunity to participate in a pretty big event in my city and want to show up with either a bunch of corny kegs or one or two full kegs. I currently just brew 5 gallon batches on my stove but want to get a large boil kettle and burner. I don't mind using plastic fermenters for this since it's a bit of a thrown together operation. I have a broken keg cooler that I can have repaired to control fermentation temps.

So what I am wondering is what is the best/most cost effective way to get a large boil kettle/mash tun. I can't weld. Do I just buy new or look for someone who can fab something up out of an old tank? Do I look for one of those brewing systems (used of course, they are expensive new). I figure once I get the beer brewed I can figure out how to keg it. Thanks a ton for any help. I'll owe you all a beer when I finally open

 

[kpr121]

I have been doing 15 gallons at a time by using two keggles as brew kettles at the same time. It is a little cumbersome on brew day but we manage. I am sure this is not the most sufficient option but it is an option none the less.