Mag drives are good pumps at a decent price. One thing I would look into if you decide to submerse one of these pumps is replacing the metal screws on the pump housing with nylon screws. The metal more or less will start to rust over time and its just a good safety precaution to keep it out of your tank.

Another thing you might want to consider is plumbing the outside diameter of the pump, instead if the inner fittings. You probably won't run into the problem on a mag 9.5, but if running a larger mag they will sometimes build up enough pressure to act as an injector nozzle and fill your tank with a nice bubble cloud.

Eheims are rock solid, but somewhat pricey and not so adaptable.