Altman used to make a 50# round
base. They get used a lot in event lighting (weddings, corporate stuff,
etc.) and as many years as I've been doing that I've never seen one get knocked over. The key is to put them where they'll be safe, to
safety the top somehow,
etc. I can rent an
Altman for about $10 for a day. You'll likely never see these come up used since they never wear out.
SSRC makes one now since
Altman doesn't make them any longer. They're about $275. Good
build quality. Although they're square and a little harder to position in use, they do have a nice handle and feet, as opposed to the
flat bottom of the
Altman.
As for the
boom, Home Depot sells Schedule #40 at about $32 per 10
foot section. A plumbing supply
house will likely have longer lengths, and likely cheaper, but you'll need to buy some quantity. You'll want 1.5" ID, which is roughly 2" outside diameter.
I wouldn't use a tripod, simply because the trip hazard is
IMO GREATER than with a
flat base. And if PSSL is your actual source, there are tons of places that will sell you better for cheaper. Like Bill at ESC.
As for the electrical hazard, you're in the
lobby of a theater, not the Stones at Altamont. Just keep it neat, flush, and secure and you'll be fine.
1-1/2" OD threaded pipe, not exceeding 12ft in height (or so), with a liberal amount of 25lb sand bags (5 or 6) added to the
base, all to support maybe 4 -6 ellipoidals.
You mean 1.5" ID.
I don't think I'd load up a pipe with 4 or more ellipsoidals. When I do booms like this the most I'll put on there is two or three.