Ooops, sorry! :)

dude have a professional do your work it will save you headaches

Do a search on Cat5 + S-VHS or Cat5 and S-Video.
"KAT5" is evidently an attempt at branding the utilization of Category 5 technology.

How well does Cat5 work? I've got no experience with it so this is NOT a recommendation. I must admit I'm enticed by the concept. With no practical example I kind of feel that I'd limit it to the purposes of having the talking heads follow you around the house or keeping up with a comedy act.

I used some of ICC's pieces in my own installation and found them to be pretty nice quality for a "non-tweek" company. They have been promising an S-VHS over Cat5 Module and that item should be available about now.

[Link: icc.com]

Wallplates are paintable and come in a few colors:
[Link: icc.com]

They currently have a fibre module:
[Link: icc.com]
(While I was going down a wall I put fibre in just as a contingency.)

You can even paint the inserts as the hardware is easy to remove from the modules.

For ICC's products you'll need to go to an electrical supply place and have them order for you. My 12 port wall plate behind my TV was $2.19 before I started adding modules.

Leviton does S-Video too:
[Link: levitonvoicedata.com]
And they're available online:
[Link: smarthome.com]

If you pursue a UTP solution make certain you get Cat5e.(E for Enhanced - 350Mhz and 150Mbps)
At the price of two modules and the length of cable you desire I would think it's well worth buying those three components up front, making up a cable and then doing an A/B comparison against a "known good" cable. (Before you assault the drywall.)

Anyone have any real experience with video over Cat5 ??

I've seen some acceptable stuff over the intellix brand of baluns..

Thanks Matt: I couldn't find the Intellix brand but did some research and found something that you obviously knew, I didn't know, and Johnnie_Miami ought to know if he's going to look in this direction.

Excerpted:
"It's important to incorporate a balun when using Cat5 since the impedance specifications of Cat5, Cat5e and Cat6 are 100 ohms. Video requires 75 ohm impedance and you'll introduce artifacts to your video without a balun."

This could send the cost of experimenting up high enough that Johnnie might want to speak to someone who will install and certify the end result.

I heard that Cat-5 will only work well for audio/video application over a long distance if it is converted to a digital signal first. I did hook-up a clients analog audio signal from his computer to his stereo over a spare Cat-5 and it was about a 150' run, but it took a while to mess with the grounds to aleviate buzzes and humms.