Staten Island may be rough. Somewhere near Manhattan would probably be best. I'll be honest, I am more likely to go to a store in Westchester than SI.
It is a tough business. Before I started my telecom business, I used to import corals, fish and inverts from Solomon Islands, Jakarta, Philippines and Fiji. I did it as a "quasi-business/hobby" for a while until I got burned by a "client" for about $1,500. Before starting a store you need to line up your suppliers. Little things like blue legged hermits and Astrea snails. From Florida you can get them for .25 cents a piece, and in some cases less if you buy 500 at a time. Also, finding a reputible transhipper or wholesaler is a must.
I had considered opening a store, but the start up cost is very high to do it right and there is a reason why every store that has tried to do it has failed. (With the exception of the store which I would not shed any tears if it went out of business- New World Aquarium)
-Alfred