Glad to help.
My tank is the exception to the flow rule IMO.
When I first started with seahorses the 5x turnover rule of thumb just wasn't enough. So I started playing with stuff and gradually increasing the flow over the last 8 years. My tank was up to the 60x turnover range, but I wouldn't recommend it for everyone. Truthfully I'm sure there are far better ways of doing it, I just haven't figured them out yet, or read of the people who have.
My tank is a 30g. My sump return is about 300 gph, but I put one of those Penducter things on it so who knows how much that increases it by. I have two koralia nano's, each pointed at specific spots (the sinularia, and the purple gorg). I also have a closed loop that pushes 900 gph into the tank. It returns in the tank by two spraybars that are behind the rocks. I then covered the spraybars with rubble rock. This helps to put a lot of gentle flow through the system, and allow me to keep large piles of rubble rock for pods to breed in without collecting serious detritus.
Even with all of that water moving there are places the seahorses can go to to rest, and there food dish is the largest dead spot so the food does not blow out. I planned very hard to give resting spots for the seahorses, I never really saw the seahorses hang out there though, they kinda like the flow IME, but everyone says you need to have them.
I would stay away from firehose type powerheads or returns, get the style that have a broad base like the koralia nano's or a Seio. The larger koralia's are not seahorse safe. Seio's are with the guards are also safe. As much as I love Maxijets for everything, they are not so good in the tank either. Best is to go through a closed loop so there are no powerheads in the tank, but that is it's own challenge.
IF you decide to go through with it I'd be glad to help out. I've been kinda popular at helping people design there systems for awhile now.
Seahorse.org is a good site to read up on them. My username there is Kevin.