PerformanceBike.com has some inexpensive lightly padded cycling shorts and red blue and yellow jerseys in kids sizes. Also, Cannondale carries kids stuff too. I actually found a couple of cute frog jerseys at my LBS this spring that my 9 year-old daughter loves (6 year old son son...not so much). The Cannondale jerseys were about $35. The bike shorts at performance were about $20 the jerseys about $15.