specific functionality - donations

Hi.
I wonder what modules should i use, to obtain specific fuctionaliti my site.
I create a tools-site for game Tribal Wars (e.g. http://www.tribalwars.co.uk ; game goes on different "worlds" - e.g.: World 1 = http://uk1.tribalwars.co.uk, World 2 = http://uk2.tribalwars.co.uk etc... - one player can have one account on one World, but can have account only on one world, and do have not on others worlds)
For each world i create similar a site, but inteded for one world (e.g.: http://uk1.domain.com, http://uk2.domain.com).

Now, I try to make site for donations (hosting and programmers cost lot of money). Players may want to make donations only for worlds, they enjoy (if player have account on world 1, he don't want to make donations for my tools-site created for world 2). This is something, like "grup purchases" - some group of World 1 players pay 1 USD (every player pay 1 USD), together pay 50 USD and want to have access to my tools-site created for this World 1.

So - if anyone make donations for specific world, he should know how many money I have now for this world.

How can I do this functionality? I'm asking for name of modules, that I should use.

Sorry for my english, I'm still learning...

I know, that I can use Ubercart, but in standar Ubercart instalation - one user can buy one product for himself. Transaction is finished, when, one user fill out all forms. In my case this is not so simply...