I mostly ride a custom steel bike built by Carl Strong, see link below. For a custom is was reasonably priced (similar to the bikes you're looking at) ... he also makes Ti bikes. It was a great experience, took 12 weeks from start to when I took delivery, and it fits me perfectly. Again mine was a steel road bike, but was still less than 20lbs all in with pedals (but without seatbag).

http://strongframes.com/