You should get something that has a TEFC (Totally enclosed fan cooled) housing. The one in the pic is Open Drip Proof, which is ok is you just spill some water on it, but not for really getting wet.
If you ever plan on transferring beer, you will want something sanitary with tri-clamps.
Ours is 2 HP and it works great for CIP on our 3 BBL tanks, but you could probably go a little less on the hp, but the price isn't that different.
We bought something like this:
http://www.toplineonline.com/index.p...search&xsearch=Pumps&query=category.like.Pumps&srctype=detail&ba ck=topline&refno=116&submenu=Sanitary Centrifugal Pumps