Honestly have NO experience with their blazers, but I just wanted to chime in about LEC. Being a student, I haven't invested in a lot of those brands you listed, except J. Crew. For me, I think LEC offers very good compromise in terms of quality:price ratio. Especially when their items go on sale, you can get some amazing deals. The Canvas line does offer more fitted clothes in comparison to their mainline. I have bought some chinos, shirts, and sweaters, and with all due respect to J. Crew, the quality was on par most of the time and even surpassed J. Crew (especially true when you are comparing chinos, LEC has much better quality for much cheaper). I have an athletic build, and the small in shirts fit well for me -- not tight or restricting, but looks fitted and plenty of room to maneuver for daily activities. Generally, I have heard good things about LEC blazers, but your milage may vary. I was surprised to hear that you are 5'11 and you wear a size 36R in suits...let me know how it works out for you, and do a fit pic you feel inclined!
Lands' End Canvas is definitely on par with J Crew as far as quality is concerned, although J Crew far outpaces them in terms of styling. Not sure if that's much of a compliment though.