I would concentrate on a good clean-up crew. I have a pair of erectus in my fuge and I spend more time watching them than staring at my reef.
I purchased mine from Jorge at
www.dracomarine.org and was more than pleased.
The clean-up crew is critical because seahorses have an incomplete digestive tract and therefore they produce more waste and thus nitrates than most active, large fish.
I keep a couple of shrimp, emeral crabs, large nass (Pacific) snails,
scarlet hermits, 5 types of macro algae,
feather dusters, a few zoa colonies, couple of acans, a blasto and xenia.
I don't plan on any fish because the horses graze on the pods and are too slow to compete with faster animals for their staple diet - frozen mysis.