approximate your stock footage geo with maya geo.
Then assign "use background" to anything you want shadows and reflections to appear on. It can be found in the hypershade create bar. It's the best way for me...
Something to remember about raytracing to help your realism... Strong point lights are best represented with a radius of less than five. Otherwise more diffuse lighting (like typically found in a kitchen flourescent lightbox) would benefit from a higher radius. Examine your footage to see what works and do some IPR renders with a small portion of your shadow framed til you get the right edges.

[EDIT]
lol... I thought I read the whole thread... Sorry Hammer!
Also check out Wax for free comp software. It's a poor man's version of After Effects[/EDIT]