Novice needs advice about creating maps on alien planet
I'm GMing a GURPS Alpha Centauri campaign using MapTools. I've amassed quite a few great maps and objects from here, RPGmapshare, and Dunjinni. However, almost all of the battlemaps are earth(like)-based, and fantasy encounters that assume short range combat. I've used Maptools to create very simple encounter maps large battlemaps, but would like to create some nicer encounter maps, and make some nicer regional maps to replace my hand-drawn ones. My GIMP skills are not that good, so I was looking at Dunjinni (which seems based on tiles, not sure about how it works with hex-based, or whether I could find the right kinds of tiles for things like pink xenofungus...), and also Fractal Mapper.
Many of the encounters my players are in involve long range (maps 3000 feet or more across for shooting guns, sniper rifles, and mortars several hundred yards or more) on fairly open landscapes (there is relatively less vegetation on Alpha Centauri), with interesting landscape features (hills, gullies, rocks, creeks, and other elevation becomes very important for cover and line of sight). I've also tried other approaches - like pasting the topo map from google maps into MapTools.
Anyway, if you have any ideas for which software would work best for this, or other ideas especially for representing elevation on large battlemaps I'd appreciate it. Thanks.