As already said by jlliagre, there is no support for SMBFS in Solaris 10. SUN announced to support SMBFS by Solaris 11 (or already by OpenSolaris since longer period of time).
The package, adelsin told about, supports a CLI client, that can be used to get and put data to SMBFS. This client acts like an ftp client, and you do not have to be root to handle it. Therefore, you may also try to use it in scripts.
To have Windows 200x to support NFS is not a good idea. The package does not support cluster functionality or let itself fully integrate to Active Directory as it comes with an extra usermapping part.
I never took a closer look at Sharity's SMBFS for Unix... If you will buy it, let me know about your results, please
Greets!