Which is why I suggested something simple. IE: an odd backed card or a db backer/face card. Easy to ring in and easy to ring out, also they have lasted the tests of time. I could sit here all day naming some of the Legends who have used said gimmicks all day but it would most likely fall of deaf ears. (Doc Eason, Bill Malone, Whit Haydn, Dai Vernon, Paul Harris, Darwin Ortiz, Michael Ammar, Juan Tamariz.) I think you get the picture. But, if you are so aching to buy some super cool new gimmick than I'd tell you to buy a good book. Which book? well that depends on what you are looking for.
As for the smoke devices. Some people can make them work and others tend to treat them like a "gimmick"/gag. VAPR looks neat and the wireless feature sets it apart from the others. But, I don't really GET the point of having smoke come from a glass or object unless you are doing seances. Otherwise, it just looks rather cheesy.