Don't put this under Donationware. What you want people to do and what you are asking means you need to put this under "Personal use only". Then you can mention how to purchase for commercial use like you are doing already. Look up the definition of Donationware. Donationware means people can use it however, and that you ask for a donation if people are able to. There are a couple different licenses you can choose, but donationware doesn't seem to be the right one for this submission. I'm telling you because putting it under "donationware" confuses people and people will use your font, assuming they are allowed to, because you basically are telling them they can. Not everyone reads the description or even goes to the complete page. You don't want people using it commercially for free, right? And nobody wants to get in trouble for doing so as well.