There are more than a couple factories producing these and the only thing that is the same is the housing. The internals and the led's can vary greatly between the companies. I work with many of these companies helping them to design the internals and the layouts (the well known companies not the fly by night ones). I could recommend a few different lights but the amazon/ebay ones are often hard to tell the specific manufacturer. I do like (and have no affiliation to) Mars Aqua led's found on ebay.
Mars Aqua 300W LED (240w)
2PCS MarsAqua Dimmable 165W LED (120w)
As for hanging I either recommend installing a shelf on the wall above the tank (can sell it as a place to put pretty pictures) then hang the lights from that. Another idea is to get some conduit pipe from HD, use their pipe bender, grab some clamps, spray paint whatever color you like, drain tank and affix to back of the stand bending up and over the tank to suspend the lights.