Hi,
I have developed alot Magento shipping modules.
I have checked your reqs in details, I can develop a Magento shipping like this.
in Magento admin, will have some setting for this shipping module, you there will 4 text area boxes for 4 shipping areas: red, green, pink, blue. You can input PostCodes ranges to these boxes.
let me know your ideas.
PS: Im working on your Virtuemart project, I sent you an email, can you check and reply me?
Thanks