I have the free version of OD, and bleh I realized you cant put the tray on it
I use the free version and yep - you can't put a tray on it, but you can use a system tray docklet... I use
this one. Click the link in the description and you'll go to Nimix' other site page for instructions and info on it, and check to see if there's any newer version.
There aren't that many themes out there really. Generally what you find in the ODock gallery is backgrounds, images for shortcuts, docklets