I have a simular rack as Bianchigirll for my Daily drivers that live in the foyer. They keep the bikes reasonably tight to the wall Only thing of warning is you need to get a short bunge to keep the front wheel straight and off the wall.
The one I have is sold as "Bikes Aloft at Performance. There is a set of optional short hangers that alow you to expand that style rack to hold 4 bikes but you would have to be a good ways off the wall to allow access to all the bikes.

I'm tossing around the idea of ripping some of the sheet rock off the ceiling of my garage to allow access to the roof joists so that I can slip the bikes up between the ceiling joists to get some head room. My buddy stores his bikes that way in his detached 3 bay shop and has about 6.5 feet of clearance to walk under them.


www.rei.com and /www.performancebike.com show quite a few storage options on their sites.

With your low ceilings in your store room might want to look a a row of these on one wall. You could alternate the height so the handle bars do not tangle and get quite a few bikes on one wall.
http://www.performancebike.com/bikes..._400007_400245