While I was hanging out with the guys from Elite Gudz in the designer toy aisle at Toy Fair, NEMO mentioned that down the aisle were some really cool stackable toys that he would love to get his hand on to customize, so I took a walk and here's what I found:
Idolz are a platform toy concept a little different than the rest: they do have articulated feet & arms, and they do have accessories, but what sets them apart from the rest is the fact that the apendages are removable and the Idolz can stack on top of one another. I think what got NEMO going was the endless totem-pole-esque opportunities this platform offered him as a customizer. Idolz are about 3 inches tall and cost $9.99 each.
Gruntor (the green camo design in the front of the pic below) is the first design that Idolz made, but I bet you could contact them and inquire about DIY blanks. I know for a fact that Damien, the president of Idolz Toys, has a few blanks in his office. If he runs out and there are enough requests, I think he could be convinced to make another run of DIY blank white versions to sell alongside the future colorways. The future colorways are detailed on the Idolz website here.