A few things.
Looks like a lot of good advice so far. As far as powering your fixtures goes, given the low power requirements of LEDs, the simples thing to do, and probably the most cost effective is to get a couple relay modules for the dimming system that exists in your theatre. If it is an ETC or Strand system, it should be quite easy to get relay modules from your local dealer. If it is a leviton or other second tier brand, it may be harder.
Others have mentioned adding portable relay packs, but this doesn't solve the issue of running appropriate power to the lighting positions. Portable packs usually require two non-dim circuits anyway, so if you were going to go this route, you might as well skip the portable packs and just run power to the LEDs... Saves cost and removes a point of failure in the system.
As for running data to your units, as people have mentioned, one of the most common ways to do this from an Express is to use the second DMX output. However, if your console is in a booth in the back of the theatre, you are talking about quite a long run of DMX cable to get to the stage and up to your electrics. It may also require pulling cable through conduit and such, which may require facility electricians.
If it is inconvenient to run a whole second DMX line from the booth to the stage, you can probably add an opto splitter into the DMX line that feeds the dimmers. Assuming that the DMX line is not hardwired into the rack and there is a connection that you can just unplug, all you would have to do is disconnect the feed to the dimmers, plug it to the input on the splitter, and then plug one output from the splitter to your dimmers and use the others for your LEDs.
While there are wireless options available, I would suggest not using them unless there is no other solution. I have had great experience with the wireless products I own (RC4 from Theatrewireless), but they only come out when there is no way to do a hardwire setup (moving scenery for example).
Looks like a lot of good advice so far. As far as powering your fixtures goes, given the low power requirements of LEDs, the simples thing to do, and probably the most cost effective is to get a couple relay modules for the dimming system that exists in your theatre. If it is an ETC or Strand system, it should be quite easy to get relay modules from your local dealer. If it is a leviton or other second tier brand, it may be harder.
Others have mentioned adding portable relay packs, but this doesn't solve the issue of running appropriate power to the lighting positions. Portable packs usually require two non-dim circuits anyway, so if you were going to go this route, you might as well skip the portable packs and just run power to the LEDs... Saves cost and removes a point of failure in the system.
As for running data to your units, as people have mentioned, one of the most common ways to do this from an Express is to use the second DMX output. However, if your console is in a booth in the back of the theatre, you are talking about quite a long run of DMX cable to get to the stage and up to your electrics. It may also require pulling cable through conduit and such, which may require facility electricians.
If it is inconvenient to run a whole second DMX line from the booth to the stage, you can probably add an opto splitter into the DMX line that feeds the dimmers. Assuming that the DMX line is not hardwired into the rack and there is a connection that you can just unplug, all you would have to do is disconnect the feed to the dimmers, plug it to the input on the splitter, and then plug one output from the splitter to your dimmers and use the others for your LEDs.
While there are wireless options available, I would suggest not using them unless there is no other solution. I have had great experience with the wireless products I own (RC4 from Theatrewireless), but they only come out when there is no way to do a hardwire setup (moving scenery for example).
