99 Mountaineer radio replacement question

I am looking to replace the Mach audio radio in my 99 Mountaineer. The lights have gone out although it stilll plays. It will probably cost more to repair it then it would be to get a new one. So...my question is: Does anyone have any recommendations on a good replacement? I am looking for something that would play MP3's and fill the space that the old radio took up. It seems a bit bigger space wise than replacement head units. Anyone else replaced their radio?

Thanks