I actually have two canister filters that I originally bought but decided to go with the sump instead. I think both methods work fine but personally I like the sump method better.
I had the two hydor's is the only reason I'm using them. I plan on picking up a heater(eheim-Jager) for sump down the road but didn't want to spend the money right now. I live in Ohio so I definitely need back-up heaters. The hydor's uses 5/8" connections (same as UV unit) so removing them from the plumbing scheme won't be an issue.
Yes, the lights are overkill but it's the dimmable unit so I can run them around 30-40% power and have really good spread over the entire tank. The other reason is if I ever decide to go with a reef the lights will work for that application as well.