With the wireless network, you're probably out of luck with the wireless repeater. They usually interfere with each other.
You should be able to just run a short HDMI to an amplified splitter. Run one out of the splitter to the first TV. Run the second HDMI (up to 50') out to a second amplifier, then (up to another 50') to the TV in the Kitchen.
Something like this would do the trick:
HDMI Amplifier Splitter | Overstock.com
Then another amp on the long run to the kitchen:
Phoenix Gold HD.REP-FF - HDMI signal amplifier
Plug it into the kitchen TV and you're good to go.
You said above that you have coaxial, HDMI and RCA (red, white, yellow) cables. HDMI carries audio and video digitally, so that's the only cable you will need to run. Using two amps like those I linked above, will do the job for you.
I've read all kinds of specs on HDMI and run lengths. Get quality cables and 50' is no problem.