Doug,
My preference is for the 6" deep kit. That way I can slice and dice, paint and detail as I like. One thing I would add to a kit for these buildings- how about selling it with the 6" footprint and the shallow shadow box sides all in one. That way depending on the layout need any option is possible. Sometimes I buy a building because I like the facade and then due to space constraints I just slice off the sides to create a flat.
As far as the lighting choice, I'd prefer the yellowish light for the older style buildings such as what you are showing here.
For modern buildings I'd choose the lighting you show on the upper floor-It's more LEED Certified looking!! 
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