Stick with the less expensive smaller system, but add a resivoir. I Use a 55 gal plastic pickle barrel and that way, always have massive amounts of potable water on hand for brewing or emergency. You can get an automatic float stop off ebay for cheap.
Keg #1: Bourbon/Oak Vanilla Porter
Keg #2: Cascadian Stout
Keg #3: BMC West
Bottled: Mjolnir Mead, Lazy Daze Hefe, The Bollocks ESB, Dark Matter stout.