Mark,
if you buy the source code, you can do with it whatever you want - it's up to you.
If you want me to do some changes, I can do that, but it will not be for free for this version - say, it will be a version 01.00.05, and after you pay me the amount we agree on, you get the module, the source code and I will will release it here for other people who want it. I will also implement that in version 02.01.00 then.
I will send you my email address in a seperate mail, so you can make an offer...
Best wishes
Michael