Many have done it but I would suggest to you look for a metal derailer sprocket instead of the little plastic ones. If properly aligned and tensioned they will suffice but the plastic ones will wear out quickly.
Generally a good bike shop will sell machined aluminum sprockets some with bearings as opposed to bushings that most cheaper derailers use.
I stress that using a sprocket instead of the wheel that comes with the kits will require almost perfect chain alignment. The sprocket won't be as forgiving.
Tom