!'ve used a few HOB skimmer and IMO nothing beats an in sump unit. You can get away without a skimmer for a tank that size with just weekly w/c's but i feel they add an extra level of security and needed aeration so i always preferred a skimmer on my smaller set ups.
some of the HOB's i've used "in order" back in the day are;
prizm (yes prizm-lol)
aquaC urchin
reefocto BH100
reefocto BH300
bermuda aquatics Rogue (sucker was a tank)
deltec mce300
deltec mce600
warner marine H2
Of those, the best were the MCE600 and the warner marine H2 (edge to the H2). The aquamaxx HOB 1.5 is a good one if you decide to go that route and they are basically a revamped warner marine design.
if your sump space allows, i would recommend the aquamaxx coneS CO-1 or the aquamaxx FC80. the tuze line (9004 in particular) is also good but i'm not a big fan of the build quality (thin plastic).