Im not familiar with any of these overflow or impeller issues of the ac that are mentioned...if you don't maintain any hob filter properly the impeller will become gummed up.
Not trying to step on toes here but the marineland hobs are for amateur fishkeepers/obsolete. They are purely a mechanical filter and they are not a great one at that. No capacity for bio-media at all and they continuously become clogged up....in fact the only hob i ever had that overflowed was an emperor.
Putting a bunch of small power filters with next to no media capacity on a 125 thats at least moderately stocked is pissing in the wind. Go with a big can or a couple ac110s. Id go with air powered sponges before lining up 4 small hobs...