You could try getting a external HD tv tuner, they let you use a TV in funtion, but i heard somewhere that there is some Delay so it might be useless for console gaming, it would look sweet if you could though!
Some TV in cards have less lag then others.
I suggest you take a look on some online reviews.
But can the xbox360 handle that resolution?
I mean its not a standard tv resolution, and its quite high for what xbox's are normally designed for.