I'll start another post.
Here's a frame to consider,
http://cgi.ebay.com/1987-SCHWINN-Spr...QQcmdZViewItem
Looks like a really nice vintage frame for 24" wheels. The seller is suggesting that 650c wheels will fit but I don't think they will.
EDIT: I fixed the link to the right auction. That's what you get for not checking your links straight away.
Anthony