I would defineatly say that starting them out on Cornets is the way to go. It brings the sound closer to the young ear and allows the young player to better develop.
The OLDS is a good choice I can't deny it. However I'd be remiss if I did not mention that I happen to have a King Tempo Cornet for sale on Ebay right now that I think would work well for you also (A Shamless plug I know).
http://cgi.ebay.com/1960s-King-Tempo...QQcmdZViewItem
Good luck in your efforts..