Hi Anurag,

Try Graupner's landing gear (Eurokit retracts and struts, Liebetrau brakes), specially made for the Kangaroo.
http://www.graupner.de
They come complete with wheels and brakes and both valves to operate them. They will twist bend, even brake the main body on hard landings, but all parts are available, cheap and easy to replace. Also, Motors and Rotors stock these and will dispatch them to you immediately if you are in a hurry, they also carry all their spares.
http://www.motorsandrotors.com

They are much cheaper than Robarts and will work just as fine. Believe me, save the Robarts for a better project.

BRG
Chris