Wireless DMX

John, sorry not to just answer your question directly, but there are a lot of other factors.

Have the scrollers been selected already? Units with outboard control boxes (like Coloram and CXI) are very popular in my area, and if you have to have the box and constant power for it, you might just as well run DMX. If you're running a multicable for the lamps on the boom (you didn't say you were - is it some kind of self-contained battery job? ...) it's probably better to bundle a DMX cable (or a Coloram cable, in the other case...) with the multicable.

I would also caution that what looks like a cheap wireless system might not be so cheap if it turns out the sound department (or the institution's office network or box office scanners .... ) uses the same frequency spectrum on the same block! You said you want cheap, but I'd prefer something robust and configurable, like City Theatrical. Sorry not to be more directly helpful.

What I'm saying is, if the theater would "budget" to acquire a new wireless microphone or a few new Source 4s, why not budget for a good wireless system that will be on the shelf (and consequently "free") when a small play needs a single lamp on a desk a year from now?