Media player that can stream from wireless synology server?

Roku with the Plex client.

I'm not sure what your media library consists of, but be sure to check the Plex forum (Roku client subforum on there) as there is currently an issue with MKV files and certain audio streams.

There are plenty of threads about it on there so you can see if it'll work for you or not.

I just bought a synology 412+ because of its ability to play nice with plex. Here is a list of confirmed synology NAS devices that will work with plex.

http://www.synology.com/support/news.php?lang=enu&news_id=340

You don't need a external media server to stream content from Synology NAS.

I have just bought a DS213 and stream all my movies directly from my TV using DLNA. Synology has his own Media Server that for me its perfect.

Synology Media Server

A external media server is useful instead if you need transcoding (or content tagging), but Synology NAS can also do it with some limitations (only Atom based models such as DS412+).

Depends on how you want to do it. You can run Plex on the Synology. You then need a Plex client. A Roku will work most of the time, a Sony GTV box will work all the time ( as will a PC or Mac) and an LG TV will also work most of the time. The issue is how powerful a Synology do you have. If it is ARM based then you don't want it transcoding and so that rules out the Roku. The Sony will play the files as though they are local. You have Direct Play/ Stream. You want to be able to do that with your media. I have all the Plex clients I mentioned. Other than a PC or Mac the Sony has been by far the one that just played everything. I have the Synology 1512+ and my Roku's struggle at times if I use the Synology Plex Media Server. You can always use DLNA which increases the number of media players that will work. My A400 works great that way with Plex acting as the DLNA server.

philip