They're not technically a set, but Lot 472 in this weekend's Rago Arts auction in New Jersey proves that Knoll has been pushing the kid-sized Bertoia chair/ Noguchi Cyclone side table combo on design-y families for years.
I don't know why Knoll doesn't make the kid-sized side chair anymore, either, only the Diamond chair. But that's the real reason to go for a mid-range vintage option. Otherwise, you could just get the same pieces new. The auction's low estimate [$2,000] is close to Knoll's MSRP [$1069 + 2 @ $529], but seriously, who pays retail for this stuff? Even if there weren't a depression, you should try a little 'aggle.
Lot 472: HARRY BERTOIA AND ISAMU NOGUCHI / KNOLL Side table and child's chairs, est. $2,000-4,000, auction Sept. 12 [ragoarts.com]