Nexenta can do all this on on commodity hardware. Also checkout what http://www.ixsystems.com is up to if you want to see what they have done with FreeNAS.
I have several peers who use nexenta, whilst I love ZFS, unless I had the staff budget I'd never recommend it. Considering its just a thin wrapper round samba and linux(or illumos, I can never remember), the support should be much better.