Can't give you much advice, but I'm interested in what others think.
I was looking at the Tunze range myself, along with the Reef-Tide 4000s (£90) and the Vortech MP10 (£220). I couldn't bring myself to buy either of these, as all I needed was a small pump for extra circulation. In the end I opted for the Jebao SW-2 (£32). It's ok, but how much better are the pumps that are over 7 times the cost?