Wow! Those are some very impressive mini fig displays! I had thought about trying to collect all the Star Wars minifigs but there are so many i don't think i'd ever be able to get them all. Plus now there are so many custom ones that i wouldn't know what i was getting.
Actually at the Lego store they already have something very similar to those. They have the 1×4×6 Windows on three sides and a few other pieces to hold them together. You get 4 rearrangable display pods, you can stack them or build them side by side. It's 89 pieces for $10 in the US.