I'm currently using TVersity but would like to find a streaming server (video/Audio/images) that is a little lighter on the CPU. I run TVersity and SageTV on the same machine and they tend to bog down the CPU when I'm recording and streaming at the same time.

I've got a P4 2.8ghz, 4gb RAM, several TB USB HDD running Windows XP Media Center Edition 2005 Rollup 2. I can't use Win Media Center as it conflicts with SageTV and I finally got it shut down and out of the way. So Win MCE and Extenders are out.

I'm streaming mpg, mp4, mp3, avi to an XBox 360 and Samsung BluRay player (dlna certified).

I have good network throughput via a Buffalo NFinity bridge, with DD-WRT, on the home theater center.

Can someone recommend a server package that is lighter on the CPU that TVersity? PS3 media Server? XMBC? MythTV?
I don't need a fancy GUI or plugins for premium content.

I'm on a budget and can't jump to a more powerful machine with Win 7 yet so a more barebones media server is in need. Transcooding is okay but kills a single core CPU so I'd rather rip to compatible formats for the time being.

I've searched the forums and guides to no avail...