Within Bridge I use Button Plus by Big White Duck for the buttons throughout the admin area.
There are loads of button stacks out there but this most definitely one of my favourites. It is also a free download but please be sure to donate to this great developer.
I am a big fan of Font Awesome. It is a fast effective way to add icons to any project. You can use the code for free from the Font Awesome website but I strongly recommend Joe Workman's Font Awesome stack for simplicity. Other Font Awesome stacks are available from various developers so if you already own one just use that.