i think that you should change the poll to include species names...
i believe erectus are the best starters.
also, i'm sure you know, they need lower temps, so in a nano, most likely you'll have to run a chiller... i think 74-78 is their desired temp.... that's also reef temp BUT many people run their reefs at 79-80/81, seahorses won't tolerate that, from what i've read.
www.seahorse.org is the best online resource for ya.
i'd do a 24 or 29 nano also. 14 is a bit small to keep the temp stable.
ooo good faq.
http://www.seahorse.org/cgi-bin/faq/smartfaq.cgi
also, make sure you get captive bred ones... that will somewhat limit your species choices, but they are a thousand times hardier and raised on mysis, so they eat well. the survival rate for wild caught is beyond dismal. so please dont do that.
you can also check out draco marine (in baltimore, MD) one of the best breeders in the country (saw a presentation by the guy, he knows his stuff). i would order them from there. always get from a breeder or specialist, the occasional LFS will have captive but most have wild caught, and we need to stop that. there's more than enough captive raised to meet demand.
http://www.dracomarine.org/