I would hire someone that can implement a shopping cart for photos. where after purchase, photos without logo is sent to the buyer?
Paypal, googlecheckout or other.

Anyone has done this?

Have you checked the Extensions section of the website? I know that there is an extension for Paypal (though I haven't used it myself); perhaps it can do what you're asking.

There is also an older extension for Google check. It's also third party so I don't know if and how it actually works.

bump if any new developements

The paypal plugin was working fine before the recent upgrades and some functions being moved to deprecated, take a look at this thread:

http://www.zenphoto.org/support/topic.php?id=6424

You might be able to bump the thread or pop over to hucste's site and see if he has some contact info if it doesn't work.

Generally all known (to us) extensions and such are listed on your website.

Also please don't "bump" threads (see the forum rules, too) except you have to write something useful to them. Thanks.