Also, for an 8' Tank, Vortechs won't cover that ground.
Without 4-5 MP40s lining the back glass you will have lots of dead spots in the center.
is the tank going to have a close loop pump? otherwise,
I'd go with Tunze, Wp's/Rw's, Gyres, or possibly the ecotechs. I don't know much about them yet, either way you're going to need something that covers more length than a vortech.