Which NAS would have no problem streaming bluray ISO and AVCHD files to the M6500A over a GB LAN?

What are the minimum requirements for this to work?

Would all or any of these work 2TB Terastation Live, Synology CS407e, QNAP TS-409, Zyxel NSA 220?

Synology and QNAP will work. Buffalo has a habit of being rather slow as far as reports from consumers are concerned and seem to have some differences in setting up access and are software based raid servers which explains a lot already.

Notice that TVIX will not play bd backups in ISO format. You need to strip the movie without menus and options to get it played... Streaming will be fine. All nas exceed the bandwidth the player can handle anyway...

My choice would be QNAP. Less attractive interface, still not bad but supports NFS by default... whereas you must modify the Syno to get it done...