your best bet is to either post a looking to buy ad in classifieds, or check ebay, i have seen a few nice t3 cylinders on there. good luck trying to find a kx cylinder, i have been looking for well over a year now, have only seen 2 and one went for almost 400 alone on ebay, the other was trashed so i didnt bother with it. but i am sure if you put a thread in classifieds you'll get a few responses, and these people are good honest people here, i have never been taken for a ride yet, always good transactions thru here.
1985 KXT 250 Tecate - kx cylinder, kx ignition, bassani headpipe, answer silencer, v-force reeds, 38mm airstyker carb, +2 franks swinger, raptor rear shock.
1996 YSF240 Blaster - maxxed out!!!
Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting "HOLY SH-T, what a ride!"