Simon,
Hi – I don’t know what they’re like, but I was looking for some for myself some time ago and remembered I'd seen this site. It says they’re 25-28mm: but there’s no pictures for French Napoleonics - although there’s a pdf catalogue you can down load. They do appear to have a wide range covering officers, troopers, standard, musicians etc. Not sure about how good they are from the website, maybe someone else can advise
http://www.mirliton.it/index.php?page=5&cName=french-cavalry&sort=1a
I'm off to vapnartak on Sunday - I'll ask around for you
http://www.yorkwargames.org/vapnartak.htm
Best wishes
Ant