Building your own is a good idea. I would stick with eSATA as it's a lot faster then USB2, especially copying to and from a SSD.
I use these for years. Just bought a new one yesterday as a matter of fact, as they're both 66% full, about as full as you want to keep them lasting forever. (well not forever, but many years) The Calvaries are Hitachi 7,200rpm 16mb. I've been buying Lacies for years. Starting back in the 250GB era. When they fill up (66%) I unplug them and store them away until needed and buy a new one, as I did yesterday. (they ALL still work, many years) I had 1 WD notebook (or whatever they called the one that stands up and looks like a book) make some noises and unplugged and replace it prematurely but it does still work. (unfilled. And it worked the last time I tried it, a few years ago)
This is the one I got yesterday.