That will probably work fine as a Q-tank for your 10 gallon inhabitants, but you need to find out exactly how much water it holds, since most meds give you amounts to add to a certain volume of water (ie: add 1 capful per 10 gallons). In the end, a standard volume tank with easily converted gallon amounts is usually best. (5 gal, 10 gal, 15 gal, etc.)
You will need a small heater, an air pump and airstone, dedicated net and gravel vac (used on this tank only), and some good info on determining deseases from symptoms (many found online easily). You will need some simple (generally fake) ornaments that are easy to remove/move around and clean around. You don't want anything that is difficult to clean in that tank. You also don't want it to be too bare so the fish are too nervous.
Your snails won't pose a problem unless there are a bunch of them, since many meds you add will kill these invertibrates and add to the water pollution. This is of coarse assuming that you use it as a hospital tank, also. Another important feature of the Q- tank is that you keep excellent water quality and vacuum frequently, but this has more to do with disease treatment than just quarantining.
