I believe there are magnets that are pre-coated to be aquarium safe that you can glue to the maxijet and then have the other on the outside, or use the maxijet for an ATO or reactor pump and get on Amazon and buy the koralias anyway. Nothing wrong with upgrading.
I just upgraded from the koralias to Vortech MP10's.
It's cheap insurance. Even if it doesnt fall directly on fish / coral - if it points downward, your sandbed is toast and all your rocks and corals will be covered in sand.
I will admit I'm not one to buy on the cheap, but for a nice SW
tank, $65 for new PH's shouldn't even make you flinch!
Good luck whatever you do!