Bigger kegs are great, and don't cost a lot more than most ask for their Cornies. Look on Craigslist or just drive around your town on trash days. I was surprised how many I have seen by the side of the street after parties. Their are lots of good threads about cleaning Sanke kegs (the big ones). They only require one tap, and your kegreator will be able to handle commercial kegs if/when you need it to. They are easy to get open when you get the hang of it after a couple of trials.