And picked up one of the Amazon Fire TV. Not a box or stick but the Fire TV. Mine is the 50 inch Toshiba. I picked out the soundbar and woofer from Toshiba so that ARC would work and I have a single remote with volume control.
I was pleasantly surprised that I can control DVD and BluRay disc playback on our Sony BD/DVD player. Not all functions are on the Amazon remote but enough. Eject for example is missing so you have to tap the button on the player.
As to the Roku, I'd like to hear how your project turned out.
Hello,
In an effort to simplify our home AV setup, I bought a Roku Stick which thankfully also turns on and allows us to control the audio volume on our Panasonic Viera 55” Class 1080p Plasma HDTV, TC-P55VT30. We only need the Roku remote to turn on the Roku and the TV and to be able to control the sound on the TV.
BUT, we’d love to get better audio by using our Yamaha RX-V579 AV Receiver and still only use the one Roku remote.
Is there an easy way we can do this? To be able to use one remote to control the Roku Stick, the TV (only needs to turn on) and sound on our AV Receiver? Sure would make my wife happy. 
Thanks,
John
Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic