Most of the in hood filtration systems I've seen have been pretty much the same and rely on a bio-wheel for bio filtration. They will work fine for FO
, most inverts, and seahorses. Just keep up with the maintenance. I don't think you'll be able to get enough lighting to do any real corals without some serious mods, at which point you're back to a basic system anyway. Water flow will also be a consideration. You need a lot of flow for corals, but seahorses will not do well with that kind of water movement. They are not strong swimmers and can't chase after food that well. You're probably go to have to go one or the other.