http://212.67.202.149/~robotwars1/phpBB/index.php very useful antweight robot site, great forums and sources of information.
http://www.batteryuniversity.com a good spurce of information on batteries and what type is best for you.
http://www.sussex-model-centre.co.uk a big shop online hobby store, which contains Hi-tec feather receivers and pico servos.
http://www.e-flight.co.uk a stockist of Lithium Polymer batteries, going up to 3300 mAh! This website allows you to shop online, too.