Pizazz

This is a great value for money, mid-range robot that comes fully soldered and just requires screwing together.
PizazzDocsIt has 2 motors, powered from 6xAA (NiMH recommended) battery pack, MicRoCon controller, Ultrasonic distance measurer, 2 IR Line Detectors and 4 pretty LEDs and a simple On/Off switch.

http://4tronix.co.uk/store/index.php?rt=product/product&product_id=340