Not exactly a smorgasbord of selections for Hang On Skimmers, and I'd say that RPro is at the top there.
If you want to make the RPro better, upgrade your MagDrive to a higher gph rating, keeping in mind that you still need to get a Mag that will fit the Remora's nozzle. The next higher Mag is exactly the same size as the 3, but still puts out more water.
What is a better HOT? Maybe a stand alone would be good if you could work it right off the tank rather than a sump. I'd love to have a stand alone wo a sump. Is there such a beast?