Looks like everyone else beat me to it. Xantech. Or Niles or a few other really similar products that are pretty much identical, also available from the usual sources.

For Xantech you should first go to their site and figure out what they offer. Then go to eBay.

Smarthome has most of their stuff, but you should be paying less. The stuff is esoteric and niche, but not expensive at all to manufacture, so you know the markup is astronomical.

I have two Xantech repeaters and a couple of barrel receivers for them which I'm using with setups around the house. I've also got RF to IR via the URC remote products which allows me to target individual IR outputs instead of blasting to all at once (like the Xantech simple repeaters do).

Check out Hometech.com for pricing, it's one of the places I bough Xantech parts back in 2010 for much less than elsewhere. Don't know how the prices are today. Then also smarthome.com. But you'll likely get the best deal on eBay.

You can avoid using a new wall wart by re-using an existing one if it has 12v output and current capacity to feed the multiple devices you'll split it to work with.

Tony, this is exactly what you'll need, though I leave it up to you which specific models of each to get:

1. Power supply 12v
2. Connecting block (this has connections for IR receiver and multiple blasters - different numbers of blasters and receivers supported with different models)
3. IR receiver (lots of variety here)
4. IR blasters x however many devices you want to attach to