Donation functionality is supported by global fundraising service givengain.com.
You will be redirected to participant's donation page on givengain.com where you can select amount and donate.
You will not need to register in givengain.com, but you will have to provide basic info, e.g. email, address etc.
After you made a donation, the amount will appear in result table (it can take some time until processed).
Yes, you can create your own private event with similar rules.
You can define the duration, as well as many other parameters. Additionally, you can design your own diplomas for everyone who participates.
Start creating your event!