yea, maybe I should join my school's bike club; make some friends who actually know about bikes.
You say double tap vs STI isn't important; would try some bikes out with the different systems, as they will give a very different feel to how the bike shifts.
I've tried out STI and SRAM shifters at the LBS, and I can't say I would prefer one over the other. Just for reference, I only have experience with friction shifters on road bikes, so it's not like I'm complaining either way. Same for bike feel; I'm probably too much of a noob to distinguish anything that's not on paper.
Right now, I'm leaning towards getting Apex over 105 because it has a more natural grip. However, 105 is in theory more durable because shimano apparently went the distance in quality control, while some believe that sram's super light weight advantage over 105 is a cause for concern, and that it lacks finesse in comparison to shimano and campy.