You can find both the kits and a full range of spares at
http://www.centuryuk.com/Products/Aeroplane+Spares
They have all the SU27 bits in stock. If your'e looking for the model DON'T buy the kit caus you will throw half of it away anyway - junk radio/servos/charger/Fans/motors/escs etc, by getting the componants you will save money and the manual is available on line - but its obvious even without the manual.