/diy/ - Do It Yourself

I'm relatively new in electrics and robotics but a long term goal of mine is to build a humanoid robot. (Yea i know it will take a couple of years to make one.) The first step will be something like one of these bomb disposal robots the American soldiers use. I'm planning for ~10-20kg.
That being said i'm trying to pin down types of motors that are:
>relatively cheap
>(1) may be used in a blocked state - for gripping things, and maybe later more sophisticated limbs
>(2) high torque main motor for robot movement
Right now i'm considering getting a few wiper motors from a local junkyard because they have been used for other projects, and maybe the motors used by electric wheel chairs for the main wheels, any other ideas for economic motors?