A/B test, as previously said. But you may not have enough visitors at this stage. So put the 2 buttons, and in 3 months, remove on of them. Then you will have the best solution for your very site, and you will have a slick design.
I am exactly at the same stage of you for one of my site... I'll have a clear answer for you in 2 to 4 months :)
I wouldn't find that desperate at all. Just throw up a "Donate here" and that goes to another page with multiple options - so it doesn't seem cluttered. Can always throw some small icons under the initial "Donate here" to show what's supported if you'd like. Split test it.
"remove one* of them. ". And seeming a bit desperate shouldn't be that important. What is important is : #1 how great your site is valuable to your user : give them great content/tools/functionality #2 user experience and, and #3 monetization.
I am exactly at the same stage of you for one of my site... I'll have a clear answer for you in 2 to 4 months :)