i say 2 glass carboys is the way to go. just transfer from glass to glass and you don't get the plastic taste from beer sitting in a bucket for a few weeks. the most a 5 gal carboy can weigh is 40 pounds which is not that heavy, at all. a bag of concrete is at least 60 lbs but more often 80lbs. you move the carboy maybe 4 times and for the quality you get w glass over plastic bucket, there's no comparison. the only thing i don't like to do is trying to get that flow from the transfer. it is much easier to open the spigot and start flow rather than trying to siphon, no pain, no gain. deal w/ the siphon and get better taste on the back end.