Fantasy Map- Room for Artistic Freedom

[Runes]

Hey,
I am currently drafting a fantasy novel based loosely on A Song of Ice and Fire with influences from The Elder Scrolls, Arthurian Legend and more. I am the sort of writer that comes up with characters, places, events, etc. and then pieces the main story around them as I go along. The story takes place on an island ruled by one king and split into a number of holds, each looked after by a lord. The key story line involves the west of the island at war with the east.

With a few characters and guilds down on paper, I now wish to attack the geography, holds and lords. What I am thinking of is an island similar to the British Isles. The west is an infertile land where men struggle with everyday life and the east is a fertile, rich land. There are only two things that are necessities:
A mountainous region around NW on the map, right on the coast.
A wide body in the center of the island where a large hold sits (the center of trade).
The rest is down to you.
Here is what I would like my island based around.

The British Isles
http://www.naval-history.net/ww2mR010BritishIsles.GIF

Custom Map
http://i180.photobucket.com/albums/x...eldonfinal.jpg

Westeros
http://images1.wikia.nocookie.net/__...steros_HBO.png

Since I am still young and writing is currently a hobby, there will unfortunately be no payment. However if this book materializes and is published, you will of course be fully credited for the design of the map and then would be a good time to talk about payment. Until then...

...I thank you in advance and look forward to seeing a great artist turn my idea into reality
Many thanks.