Hi, there are many video sender devices here in the UK, most use composit RCA, they are getting very cheap hear because of our love with CCTV. I Have tried using a Phillips Video sender but found that is very suseptable to interference from other devices such as wireless networks, UHF radio mics. The picture used to jump every time a large number of people got in the way of line of sight if you see what i mean. This was about 2 years ago so perhaps they have improved a lot. The ones made for wireless ctv seam better but they are often used with low output cameras so you might find the picture over saturated with the output from your computer and they are often limited to 4.3 ratio.
Also the sender and receiver shoul be plugged into the same ring main or interferance tends to be worse.
Can't beat good old coax
