For wired I would go with either
Clear-Com or
RTS analog partyline. Technology hasn't changed much since the 70's, and you should be able to find used gear pretty easily.
Clear-com's
current Encore 700 series belt packs are good but still pretty new, their previous 600 series isn't too popular as the boxes tended to break, but the older still 500 series and older are still popular. I volunteer in a
theatre still using 2nd generation
Clear-Com boxes from the 1980s and they still work fine. All you need is a
power supply, beltpacks (most likely 1-channel versions), and twisted pair cable tying them all together.
For wireless, cheaper systems may work but it depends on the specifics of your
venue. If you have a wireless
base station that's within 50' of the users and
clear line-of-sight at all times, then a cheaper wireless intercom
unit may work. If you're in a larger space with massive concrete walls, and your wireless crew need to run around and talk everywhere in the theater, then you may be better off waiting for more funding to
Clear-Com Tempest or similar. In general, intercom is the one
system in the
theatre that must work when anything else fails. Test whatever wireless
system you opt for in your
venue and all locations, and money spent on an unreliable wireless intercom
system is wasted IMHO, since dropouts are never acceptable during a show. A wired
beltpack with an extra long
XLR cable can sometimes work better than a flaky wireless
beltpack. If needed,
Clear-Com's TW-47 can interface 2-way radios into a wired intercom
system.
