Jansen,
I used to use AV transmitters but got sick of interference and intermittent IR performance (I have a double brick and steel house). I have gone with some quality 3 way single core shielded cable for straight AV with RCA, ie composite + LR audio, this is used for Foxtel not running through my MCE. I am quite happy with the result.
The cable is a bit like this
http://www.dse.com.au/cgi-bin/dse.st...uct/View/W2007 (I can't find the actual one on-line). It is blue, has a slightly larger diameter strand for the video. It is designed to carry LR + Video.
I have two runs of this, a short one (15m) to the lounge room 37" LCD and a longer one (25m) to my downstairs games room to an older 34cm CRT. The rugby and music channels look fine on both.
SVideo is definitely a better quality (ie I use it for Foxtel to the local MCE), but personally I have never tried to run it over any distance.
I use no amplification, but I do have multiple outputs on the Foxtel box. For one run I do just use a "Y" splitter, not problems there. If a "Y" split fails you amplification can always be added later.