Xbox viability and making video go where you want it

What i want is to use NAS to store video, audio, and pictures. I then want to stream or serve it to my TV in HD, without the use of an actual PC. Two reasons for this. One, I havent seen anything offered for PC that... and I stress this, that I find viable. They dont interface well they only act on top of something like XP or Vista, their bulky/noisy to keep cool, expensive to build, the software is quuirky at best or limited or proprietary and the navigation leaves much to be desired. Complicated. Two, I dont have a whole theatre PC worth of funds, i.e. thousands of dollars.

I own a Samsung PN42A450 Plasma TV. I also have an unopened arcade 360. Now I have done alot of reading and searching and talking with people. To my understandiing the easiest way to do this is to sell the 360 buy an original xbox mod it with something like XBMC and using a component cable I could stream in SD, HD, etc.

Is there a mod community for the 360 that makes it so i do not have to use twonky, or a PC with MC? how viable is the original xbox at HD and serving up content?

What are my other options? Theres theatre PC's running MCE, Apple TV, the whole xbox solution, what else?
Isnt there some sort of box? juicebox or slingbox? This is new territory for me. i've built PC's for years, and I know about HD, but serving and streaming are new to me.

If I've overlooked important info or need to answer some questions I'm open. i appreciate all help any gives and thank you!