UPS Suggestions

Hello,

Didn't know exactly where to put this.

I have a new server running FreeNAS amongst other things and would like to guard against power failures. I have never owned an UPS, and sadly have no clue what constitutes a "good" unit.

What else, besides power output, should I be looking for? I would like it to be fairly compact, and will only be servicing a MiniITX server with 8 drives and 2 ssd's.

Thanks for the help!