How do i go about modifying/customizing vB icons?
 

Id like to match the color of the default vB icons to my customized style - whats the best way to go about this? Any certain program?

Are there any sites that offer sets of transparent-background icons for use in vB styles?

Either create your own images or have a look in the graphics sets available at vB.com to see if there is anything that will match. Then upload them to your images/statusicons directory overwriting the existing ones.

You can use the graphics kit in the members area and manipulate them using vButton (iirc its in the graphics forum on vbcom).

You can also use the "small" or already compressed graphics kit from vb's members area and use photoshop to adjust the hue/saturation levels of each image to change its colour.