Quick HDMI Cat5e/Cat6 Question

I know that this has been asked throughout these boards but I just need the closure of my question being answered so I don't mix something up. I am mounting my projector about 40 feet away from the receiver and running the cable in wall. I have read that longer HDMI cables can degrade the signal so i am thinking that the HDMI Cat5e/6 extender is the way to go.

First what is the difference between Cat5e and Cat6?

Is this stronger than running a long HDMI cable through the wall? I would rpobably use this extender from Monoprice.

http://www.monoprice.com/products/pr...#specification

Do I need one Cat5e cable and one Cat6 or can they both be the same?

Any help is so so so appreciated!!!

thanks! Will this be better than setting up two basic hdmi wallplates with a 40 inch hdmi cable running through the wall. Then using 2 three foot cables on eacc end to connect the sources to the wallplates?