you may be well served by test riding as many bikes as you can. Boston is sure to have many bike shops. Go try every bike your size even try one a size larger and smaller, relaxed geometry, race geometry, carbon, steel, alum, titanium, 105, ultegra, Force, Red, etc. Record make sure you know understand the properties of each.

once you understand the performance that you can expect, you can go find some good deals on Ebay. an extra 800 for Dura-Ace for some it's worth it, for some it's not. Some only buy new 105, because they think it lasts longer. Depending on what you prefer you can build a very cost effective ride for $1000, or $3000, or $5,000. I just depends what you prefer. Being able to wrench and having access to tools and experts, you really have no limits.

Once you start getting ready to purchase, I highly recommend Ebay. Plenty of reputable sellers as long as you have some flexibility on time and brand you can find what you need. If needed you can go custom frame.

Best of luck. look forward to seeing the build. BTW it took me 3 months of testing new and used bikes and 3 weeks of ebaying to find and build ride that was perfect. I was open to all brands and searching for a solution to what I needed and was not pigeon-holed on a certain brand and component mix.

BTW I pick out a Giant carbon with Dura-Ace, only because it fit and was a better value than any new or used bike I tested. At some point you just have to build it, tune it, and ride it.