Regardless of whether your units are gas or electric, I would keep my booth separated from them by as much space as you can allow. Especially the exhaust portion of the booth. If you buy a booth from a company such as Artograph, which has a charcoal filter to adsorb any vapors, the hazard risk should be somewhat less; regardless, organic vapors need to be kept away from flame or any other potential ignition source.
Gip Winecoff