HTPC that streams media from my HP Media Smart EX495

To be quite honest my brain is fried trying to price out/put together a good build that is inexpensive. I made the massive mistake of purchasing the WD TV Live Plus to stream my media...tried for 4 days to get this thing to play the "supported formats" in the end i could only get it to play ISO's which they say is unsupported. I almost tossed the thing against the wall, if anyone wants it, let me know and I'll sell it to ya hah.

Down to business though, i'm looking for an HTPC / Media Player that connects wirelessly to my network and streams media from my HP Mediasmart EX495 server. I know wired is better but i'm not trying to stream HD content or Blue ray content. Eventually i may get there, but i have over 300 dvds to start out with before i move on to anything serious.

Listed below are the specs i'm looking for.

PPROXIMATE PURCHASE DATE: Today / This Week

BUDGET RANGE: $250 before rebates or after, doesn't matter cheaper the better

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: n Wireless (built in preferred), Streaming Media (movies, audio, pictures) / Browse Internet / Play HD Content / Games / Store locally

PARTS NOT REQUIRED: Keyboard, mouse, monitor, speakers, os

PREFERRED WEBSITE(S) FOR PARTS: newegg.com

COUNTRY OF ORIGIN: U.S.A

PARTS PREFERENCES: I would prefer an AMD processor since they primarily are chepaer than Intel..however if intel is the way to go i don't mind.

OVERCLOCKING: Maybe

SLI OR CROSSFIRE: Maybe

MONITOR RESOLUTION: 1920x1080

ADDITIONAL COMMENTS: I would prefer for it to be quiet and run cool, i won't technically have it running 24/7, i'd rather shut it down after viewing/streaming media and i'll be utilizing Win 7 with WMC auto start up when computer starts. I may eventually move to XBMC for more lightweight but my whole house is win7 right now so i'd like to keep the same UI across all the laptops etc. when they stream WMC from the server.

I'd rather not purchase a pre-built system since upgrading those at a later date can prove...disastrous. However, i have been outside the builders community for the last 5 years...always have built my own systems but when it gets to what requirements i need to streem h.264 codec and audio codecs i am a COMPLETE newbie.

I've looked at many HTPC build threads but it seems they are mostly for stand-alone HTPC systems with 2 terabyte hard drives...since i already have a server i don't need that....i hope this is not a redundant thread that i just failed to overlook.

Thanks in advance,
Jeremy