One more vote for a Magnum 350 using the micron filter. I've used these for years on my Rift Lake tanks with great results. I also run a Vortex on it once in a while, but like the fact that the Mag 350 can be run continuously. The only problem I have with the Mag 350 is that, when new, I find they suck a lot of air into the canister (from God only knows where! Probably around the canister seal), but this often clears up in a week or so after the o-rings get settled.
I'm currently running a 350 on a sump under a 70 G Oceanic Tech, in the final chamber before return to the tank.
- KW