Welcome back! I have no personal advice on buying a big bike since I have quite opposite your problem (4 foot 10).
But...If you want to be custom fit or at least get some advice there, Anne has helped fit cyclists on both ends of the spectrum. She is at Running Away Multisport on Clybourn.
AKA Paul is way over 6 foot and he has a few bikes. (and if you need a dog walker in the lakeview - edgewater area he does it all by bike!)
Welcome back! I really like Roscoe Village Bikes. Not in Logan Square, but not terribly far either (Damen/Roscoe).
you're almost a foot taller than me (5'11" and inseam of 86cm) and yet we're riding the same size. unless you have an odd inseam/body dimensions, I'd guess your bike fit is off. there's only so much adjustment to be made with a stem, seatpost, and saddle setback. you say you're comfortable now, but I'd wager you'd be even more comfortable in the 62cm+ range. maybe try the competitive cyclist fit calc to get a rough idea, but bike fit isnt an online thing. head to a good shop instead.
To fit you well, you'd probably be looking at a 66cm+ frame. Something more like this: http://chicago.craigslist.org/nwc/bik/4007717821.html
Hard to find frames that big, but when you do I think you can sometimes get a good deal - not much of a market there.
Logan Square and Wicker Park aren't a contiguous area. Smart Bike Parts on Armitage, Bike Lane on Milwaukee, Boulevard Bikes on Kedzie, all good choices in Logan.