jQuery Themeroller design refinement for drop downs

I have search engine that uses make, model and year drop downs to narrow the search. In an effort to move to an OS independent appearance, a prototype page has been created using Themeroller. So far the appearance of the drop down boxes has successfully been made OS independent, but that of the scroll bars has not. I'm not sure if Themeroller has native elements that can be used for this purpose. If not, perhaps jScrollPane or something similar could be used. I would like to accomplish the following: 1) Make the scroll bar appearance compatible with the rest of the design. 2) Make the scroll bar appearance independent of the OS. or Use an alternate technology to scroll, perhaps with "odometer" like scrolling (i.e. where there are up and down arrows next to a box that's a single line of text high), rather than a drop down. or We had considered making the drop downs very tall in order to eliminate scrolling, but the limitation seems to be the height of the frame the search resides inside. If there is some way around this, we would be willing to reconsider this as a possible approach. 3) Make sure that the appearance is consistent across common browsers (we were led to believe that this part would be particularly difficult). The page currently uses Zope/python, CSS, mySQL, javascripts, and jQuery Themeroller.