I want to use my wired kbm from across the room

I just purchased a steam machine for living room gaming (I already have a much more powerful PC, but it's in my office and sometimes I just want to play my games from my living room couch with my wife. Go ahead, get your clowning out of the way.

I expect to still want to use a keyboard and mouse for some games and already have spares I like. I don't want to buy a new RF keyboard and mouse so I'm hoping there is a good option for plugging my existing setup into a RF transmitter.

Can someone recommend anything that could help me here?