I love my Reef Octopus 150g skimmer; it's a great brand. The last post was from two weeks ago but if you're still in the planning phase, may I suggest overcoming your aversion to a sump? Wait, wait, before you groan, just think of all the nice benefits: doubling your water volume and thereby making it easier to control water quality; 2- you could run an in-sump skimmer, or run the HOB skimmer in the sump; 3- you could enjoy the DIY process of making your own sump (it took me one afternoon to do so, more on this later); 4- you could park a refugium chamber in the sump, add a basketball-sized ball of chaeto, and export nitrates (also would give you a nice microfauna food supplement; 5- (this one is a big deal) you could have a high-powered return pump that keeps detritus from settling, without having to use powerheads!
I have a 30g cube with a 300 gph closed-loop and also a 500 gph return pump. That might sound overkill but it's evenly dispersed throughout the tank (mainly at the corners). I installed the closed-loop so that I could remove a Hydor nano (I think this is the one you're planning on using). I was horrified one day when my female H. Barbouri seemed to get stuck to the side where the intake is; she had her tail wrapped around the sidebars...scary stuff, fortunately she wasn't injured.
If you have the space nearby to put in a 20-30 gallon aquarium/DIY sump, it gives you more options. I used a couple of panes of plexiglass to install a filter sock, trickle filter (to prevent ammonia spikes), refugium compartment (20g or so), and a small section for the return pump, the refugium pump, and a heater. It's an ugly ugly piece of work but I'm very happy with its performance over the past year.
If you think you might want to use a sump down the road, but don't want to worry about it yet, maybe consider having a glass company drill your tank. You can install a bulkhead, stick a plug in it, then have the option of connecting the tank to a sump later. Once you cultivate your sand bed, it'll be too late to drill the tank, and overflow systems always over-flow onto the floor once or twice a year lol.
Anyway, there's plenty of good options for you, but consider using a closed-loop or return pump in order to generate the healthy flow you'll need. Seahorses and powerheads make me uneasy - prehensile tails, moving blades, intake holes, etc. Dan Underwood (from seahorsesource) gave me the idea to use strong return pumps instead of powerheads by the way.
Lee
