Using an XMOS startKIT as the "brain"(I'd be open to using an Arduino, or a Raspberry Pi, but what I have is a startKIT), I'm going to build a replica of K-9 from Doctor Who(MkI or MkII, not the "suped up" thing they did for that Austrailian kid's show). Progress will be slow due to current lack of money and other supplies. I am fully open to any advice on design, or where to get needed parts cheap.

Features I'd like to include:
Voice Recognition(simple commands)
Voice Response(If I CAN I'll have it mimic John Leeson, the original voice of K-9)
ability to avoid objects(I don't want it to be remote control)
self charging(either via homing in on it's charging station, or solar panels?)

whatever else I can fit in it


Have:
XMOS startKIT for the processor

Need:
battery(rechargable)
wheels
drive motors
wheel base(18"x30")