I've been using an urchin on my 45 for about a year. Definitely get the maxijet upgrade; it works way better. In fact, I'd think about an urchin pro with the mag 3. I borrowed an EV120 for a while, and it pulled way more junk than the urchin on the same system, and my tank looked better. (it's pretty heavily stocked with sps) So the urchin pro would probably do better in the long run, because you can run it with a better pump. Just my 2 cents.

Matt