Bouton d'Or has a 100% angora yarn that's *machine washable*!! It's called Infeutrable. It's very pricey though... like $25 for 30something yards. That rings up to just shy of $1000 for a sweater. *choke gasp choke*
Anny Blatt has a 70% angora for a better price, still pretty pricey though.
You could check ebay... I snagged 7 balls of Bernat Dreamspun (70% angora, 30% lambswool) for $16! It's very very lovely stuff, but sadly, not produced anymore. :(