I personally feel that form is more important than shoes, although shoes are of course important.
Get a copy of "Born to Run" from the library just to get stoked, and also for some of the thinking behind minimalist shoes. Also recommend Chi Running for form suggestions and the emphasis on running efficiently and injury free.
I run in shoes from 4mm (primarily) to 12mm drop, and feel that switching between different shoes is good for your feet. One thing I will say is that since switching to lower drop shoes, wearing high-drop shoes feels like crap. Like wearing clogs and no feel for the ground. Will not go back ever. I've also found that wearing low-drop shoes has strengthened my feet and arches noticeably, so that I've now done away with all arch supports (Sole/Superfeet) in my shoes (except for cycling shoes).
Based on this, I would recommend shoes between 4-12mm drop with relatively low stack height and a flexible sole. Work more on form and worry less about shoes.
I would pick North Shore Athletics, Kintec, and Forerunners over RR any day. Forerunners has the best selection on the Shore, all three have great staff.
"The song of a bird…We used to ask Ennesson to do bird calls. He could do them. How he could do them, and when he perished, along with him went all those birds…"-Return from the Stars, Stanislaw Lem
"We just walk around, and sometimes we go out and dance, and then we listen to the environment."-Ralf Hutter, Kraftwerk