Best site & strategy for Previews/Trailers?

Like everyone else, I often end up dumping “bonus” information, including previews, from DVDs to allow for improved picture quality on backed-up DVDs. But my wife prefers viewing trailers to reading movie reviews, and I’d like to accommodate her by putting a bunch of previews on a DVD. That way we could skip changing disks once for every movie we wanted to consider.

Is there a good web site to visit for viewing / downloading just the trailers? I’d need some way of converting data to MPEG format too I guess. I can do Streambox if my only option is to capture a stream. My preferred player for this sort of thing on the PC would be Media Player Classic, and ultimately I’d like to be able to see the previews on the PC or standard DVD player.

Any suggestions on best ways (favorite software) to convert files to something a standard DVD player could understand also appreciated.