Welcome to the club!
Well, there really aren't many different accessories for the Nano - you've got dry stems, and GonG's to pair with water. You can buy your accessories direct from EpicVape.com or you can order custom glass accessories from
@VaPeD&CoNfUsEd - he sells several different glass accessories for the Nano - just peruse his glass thread and you'll see what he can do.
A SteamRoller is simply a type of glass with an open end on both sides - you use it dry and cover your hand/thumb over one side while hitting - remove your thumb from the other side to "steamroll" the hit. I prefer this piece over the traditional dry stem simply because I can keep my nano inverted the whole time (to prevent ABV dust from falling into the heater - I'm really OCD about ABV dust)
GonG's come in various shapes/sizes to fit the standard glass bubbler sizes. You can purchase 14mm or 18mm male GonG's direct from EpicVape (these fit into a standard 14/18mm female on most bubblers).
@VaPeD&CoNfUsEd Also sells these, but with an optional "carb tube" to help prevent ABV blowback. He also sells female adapters if you are purchasing an oil-rig type bubbler with a male fitting (frosted side of the tapered glass helps indicate male vs female - if frosted glass is on the inside of the piece, it's a female, frosted on the outside it's a male)