I would suggest you head over to the Dungeonforge website at http://www.dungeonmapping.com/df/pub...hp?name=Forums
There are two programs there, and the one called Dungeonforge (NOT MapX) would probably do exactly what you want.
From the quick blurb:
It is free in the download section (but you might need to register in the forum). The nicest thing is that it will work with pretty much any graphic file for the tiles, and will auto-wall as you mark the floor tiles.Dungeonforge is an easy-to-use map creation program for Role Playing Games. It is fast and flexible and can produce maps in the style of Dungeoncrafter and Dundjinni (as well as using the same range of art).
The maps can be printed for tabletop use or used in online games.
Can use any PNG, JPG, BMP art.
Cell size range from 20x20 to 128x128
Maximum world size 200x200 cells
Maps easily used and edited by other Dungeonforge users
There are a variety of tile sets, from photo-realistic to classic TSR, also available in the download section there.
Give it a try. I still use it a fair bit, depending on the map style I want. The community is pretty active, and great for answering questions. I pop in often as well.