Recommendations for NAS and Media Center Backend
 

I have all the hardware, now I'm looking for what all to install.

I want this to be primarily a NAS with web management similar to freenas or openfiler. How does webmin stack up against that? Are there any others?

I will not actually be using the system as a frontend. (it'll be shoved in a closet/corner). How does mediaportal stack up against mythtv as far as a frontend/backend scenario and hardware support? ( my tv tuner is hauppauge 1800 hvr )

Any suggestions in software or distributions to check out would be appreciated.