Being a big fan of Blueprint CSS, I've been finding it very useful on that purpose. Give a try. http://www.blueprintcss.org/

Or keep searching on Quora & Stackoverflow. Here is an example that might be working for what you've been searching. http://www.quora.com/Are-there-any-web-2-0-UX-UI-development...

Focussing on Javascript UI libraries could also work. http://speckyboy.com/2010/05/17/15-javascript-web-ui-librari...