I say go for 105's if you can. I got Ultegra SL's, and they're awesome!

As for the bike shop, deal with the people you like and avoid the ones you don't. I've had really great experiences at a couple of LBS's, and I've had such horrible experiences that I won't go back to two of them. My husband broke a spoke when we were riding the other day, and he didn't have spares. He took out the broken one and then trued up the wheel the best he could. He then took it very slow back to our car, 25 miles away. He went right past an LBS that's right on the trail and kept going because we can't stand them. We loaded the bike in the car and then drove 40 miles to get to our favorite shop (30 miles beyond our house) to have them repair it. They also sold him some spares and showed him exactly how to replace them for future problems. Go to people that treat you like a customer, not an interruption.