About the only ones that do in your price range are rear projecton CRT HDTVs.
Most digital TVs have a native resoultion, most Plasmas are 1280x720. What they do is scan convert the other formats to 1280x720 and then display it.
Some of the DLPs will do 1080i native.
The best thing to do is go to the manufactures web site and get the specs.
Here is a good link that may be helpfull. John
Does anybody know of any model of tv that supports all 4 definitions(480i, 480p, 720p, and 1080i) from either 30 inches up to 50 inches over $500.00 and under $2500.00, any help would be apreciated, i have searched online but nobody seems to be able to give me a straigth answer when it comes to this.