Pretty please, Cartographer's Guild, I reach to you in my hour of need! I'm trying to design a campaign world, but my efforts at mapmaking have brought only shame to myself. Ideally, here's what I beg of you to help me with:

Project Scope:
Moderate scale island continent roleplaying map for D&D campaign setting. In a nutshell, I love designing worlds, but suck at building maps, so I use a general pre-created map and tailor my nations around it. What I need is a world mapped out roughly the size of Asia. This would be just basic geographic features, no need for names or nation borders. I'm pretty much just using this as a starting point.

Basically I'm looking for your standard D&D style campaign setting map, not unlike Eberron or Greyhawk. Geographic features and landmass sizes I leave entirely to your discretion, but I will need the following: 1 large island continent (with room for approx. 25 - 30 nations of varying unspecific sizes) seperated by a large island-filled sea from two smaller island continents (2/3 and 1/3 the size of the big continent, respectively). No need for polar caps. As far as climates go, standard Earth-like geography and ecosystems will do fine, but I'll need at least one large sand desert on the main continent, and mostly jungle terrain on the smallest continent. The large sea in the middle will need at least 2 clusters of islands, and at least 2 country-sized islands, and a few scattered small inconsequential islands. (Sorry for being specific after saying I didn't need it to be; I have a half-idea of what I'd like this world to look like).

Design Concept:
Basically outlined above. For exaples of what the final product of this will hopefully look like, see here:
Details like topography or tectonic plates or water depths I don't really need. I have a working copy of Illustrator and Photoshop, so I will add things like towns and names and borders on my own. It doesn't need to be super fancy, but something that wouldn't look out of place in an old-style atlas would be nice to see.

Number of maps:
One world map. If created in photoshop, layered so that the outlines of the landmasses are on a seperate layer, if possible, so I can reproduce if need be with various filters showing topography, national borders, areas of influence, etc. Note that I don't need these filters made (I do have a working knowledge of Adobe products), I just need a geographic world.

300 dpi minimum. Jpg, tiff, or png files, along with the associated working file if possible, (only AI or PSD file types).
Full color
Vector preferred, as I'd like to eventually crop and zoom on certain areas to flush out details.

Remains with cartographer.
I'd like to retain the right to reproduce the maps in a setting sourcebook or post online, which, let's face it, probably won't see commercial production. If it ever does, we can negotiate maybe some kind of royalties or something down the road for sure.

No fixed deadline. Frankly, anything to work with, even if it's just some spare thing you've done in free time is more help than I could ask for.

Was kind of hoping this would be free, but if the work is just really damn good, or I plan on publishing it or something, then we can negotiate something down the road. I'm not looking to scam someone out of hard work here.

Please use subject line World Map

Thanks for your time, guys. Really like the stuff I'm seeing being made around here. Very nice!