You could also consider a p2pool (such as http://216.249.119.195:9173) even if you don't use them as your primary pool, they make excellet failovers.  If one node were to go down, the others stay up and you can switch over to a different node without worring about having to wait till your pplns payout goes up (they're all part of a decentralized network that keeps track of how much work you've done on the p2pool).