If you want custom maps Chessex makes some nice “write on”/“wipe off” 2" hex mats (they make 1 1/2 " and 1" Hex Mats as well). To match the scale of the maps the 2" Hex Mega Mat woudl work.

Here is the description:
Using water-soluble overhead-projection pens (NOT dry erase, grease pencil, or permanent markers), you can write on the vinyl and remove later with water when the adventure is done.

http://www.chessex.com/mats/Battlemats_MegamatsReversible.htm

Sizing: Battlematâ„¢    = 26” x 23½” (66cm x 60cm)
Sizing: Megamatâ„¢        = 34½” x 48” (88cm x 122cm)

96259 Reversible Battlematâ„¢ 2" Squares and Hexes $19.98
97259 Reversible Megamatâ„¢ 2" Squares and Hexes $34.98