I found a Donation mod called Treasury ( http://custom.simplemachines.org/mods/index.php?mod=916
) that has the possibility to work with ezPortal to create a block which, in my opinion looks great.
The official site of the mod is this one: http://resourcez.donationspro.com
and has a Free and Pro (paid) version of it. I'm using the Free one and it's works great (for more info, check the links to mod and official site).
To add a block to ezPortal, just create a Donation block on the options of the mod and then create a php block with this code:
I think this is a good solution for those looking for a Donation block.