I use a
Terk Leapfrog system, under $30 delivered when I ordered it from Amazon a couple of years ago. IR target/RF transmitter is in the front of the room on the floor next to a speaker stand. RF receiver/IR repeater is inside an armoire at the back of the room, probably 20' or so as the crow flys. The IR repeater sits on the bottom equipment shelf and it's cabled IR bug sits loose on a middle shelf. IR repeater is powerful enough to bounce enough IR signal off the *dark* wall 4' away from the armoire and still get pretty consistent equipment response. With the doors closed (SOP) I've never had a failed command that was acknowledged by the target (flashes LED). No apparent RF issues from target to repeater and we have 802.11, cordless phones, baby monitor, multiple computers, two different cell phone carriers, etc. competing for spectrum.
-Brent