The icon set illustrated is the fabulous default icon set for Mint 10.If you haven't got the Nodoka engine, it's
sudo apt-get gtk2-engines-nodoka
or in Synaptic. Pardon my lack of a full installation file but hopefully the screenshot will make someone reading want to try it all out, a few minutes' work. The panel background tiles the length of the panel - put it in a folder and drag it to the panel. The white text on the panel begins after the gtk part of the theme is installed, dragged in the Appearances > Theme window. I am using a panel 25 pixels high myself, this does trim the menu icon a bit, which doesn't trouble me, but I've since made a smaller version of Merlwiz's leaf icon 25x25. ***To change the MintMenu icon if you never have, right click on it, click Preferences and then type in the folder/file path to where you've put the menu-leaf-3.png file in the box marked Button Icon.