auto dimmign mirror, question

Hi, I've written before about wanting to add an auto dimming mirror to my
accord. my local dealer wants 300 bucks to install this. I've been looking
at a few after market ones, one I found at
http://www.sigmaautomotive.com/NVS/nvs.php it is the one all the way on the
left.) cost is 77 dollars and 10 for the "foreign vehicle bracket" needed
for a honda. so total price is under 100 wiht shipping and a local car
audio/video shop said he can install it for like 25 bucks for me. Does
anyone know if theres a mirror that has homelink buttons as well (without a
compass or tempt sensor or anythign)? I cna't seem to find one. Has anyone
installed an after market auto dimming mirror? the fact you have to take
down the overhead pannel and wire it in make me a little worried. basically,
if there was an issue with say the pannel (or the microphone for the nav)
would honda still cover the warranty? sorry for all teh questions. thanks!
-Nick