As long as you have SwitchResX installed on the Mini, the only thing you really have to worry about is buying a TV with HDMI. If you don't want to have to worry about SwitchResX, just get a TV with dot-by-dot (or 1:1) capability. Thankfully, most TV's have this now.
So, just buy the TV you want and worry about the Mini later. Whatever you buy, the Mini will work with.