I suggest a cabinet style smoker, like a backwoods They are insulated in most cases, so you should not have to worry about being close to railings. Offsets worry the jabberers out of me on a wood deck. I have done it but it was on a fire matte with fire board around the back side, along with extinguisher and garden hose close at hand, this from someone who like to play with fire. I have not checked backwoods prices in a long time so I can not speak to that. Also may want to check your city codes.
Lg Spicewine on trailer
Weber charcoal grill
2 ugly drums, semi retired
Bbq toolbox, formerly Chargrill smoker
My wife has gas, its a Brinkman.