Head to your local hardware store for the following 3/4" pipe and fittings:
2 ten foot lengths of PVC
3 end caps
1 threaded female hose connector (slip fit)
2 elbow joints (90 degree)
2 T connections
1 pack quarter circle mister jets (12 count)
If the option of chaining your KidWash with other water toys interests you, just pick two end caps and add:
1 threaded male hose connector (slip fit)
1 hose cap
Note: you want the PVC hose connectors, not the more expensive metal fittings. Don't give up if they're not with the other PVC fittings, I found them by the sprinkler parts.
The misters used here are from www.mrlandscaper.com
, a brand carried by Lowes.