I’ve just spotted the MeArm Robot Arm while browsing the interwebs. Looks interesting. A few servo motors and a driver board in addition to the various parts. The whole thing is open-source so it could be worth grabbing the files and trying out. I might need some more powerful servos than the cheaper plastic-geared ones that I’ve been buying.
MeArm is on Thingiverse and can be bought at 4tronix