I was planning on building up a new road bike- Had my eye on a mid 2000s specialized roubaix carbon frame, would have cost around $400. This would have replaced my trek 1000 from 2001.
Then, I built up a conversion fixed gear. This is on a 1990 Trek 400 frame, and I'm in love. I'm considering upgrading this setup, starting with a new frameset.

My tastes:
simple lines (leaders are nice and all, but I'll leave that look for when I get my triathlon specific bike)
Level top tube- sure, call me superficial.
I like the look & feel of lugged steel, but I'm open to other options.
I would like (but don't require) a water bottle mount.
Light weight is always a plus, but not at the cost of durability. I'm 160 lbs +/- and 5'11''. I can easily enough do 150 miles/week, though often it's closer to 75 because of work or school.

It may or may not end up with my celeste velocity deep Vs on it, since the trek will be getting re-painted in dark silver & celeste (lugs)

Frameset suggestions appreciated, even if you only hit a few of the above points!