Yeah, I agree with the rtc. Eventually you'll have one large fish in your tank....
Id vote sump, but thats just a personal preference. They move tons of water, are pretty easy to build and are very cost effective. If I was going to do a canister Id skip the xp4. I love my xp3's, but the xp4 is no good. Pair of fx5's or 2262's would be good