Cheap system advice...

Friend of mine if building a cheap system for some children. He was going to build one based on a Cyrix PR166+ but I convinced him it would be better to go with something socket 370 (Cyrix III or Celeron?) especially with upgradability to a PIII at a later date. Need advice on a good motherboard, with definite Cyrix III support preferably and integrated sound and video. I was thinking along the lines of the VIA PM133 chipset (integrated Savage 4/2000), the Ali Aladdin TNT2 chipset (integrated TNT2 obviously) or maybe one of Intel's many i81x. Something with enough 3D performance to get by, that is cheap and supports the Cyrix III.

Got any ideas?

Oh and is it true the Cyrix III can run with only a heatsink? That would be an added bonus.