FWIW, I have several bikes that are built using high end lugged steel frames from the '80s or early '90s with modern (well, at least 10 speeds in the rear) components & wheels. With a "vintage" frame you may have to (or want to, at least) re-space the rear dropouts to 130mm, but that's not a big deal (just be sure to check alignment afterwards....Google will explain). You could check out the retro-roadies/STI (or something like that) thread in the Classic & Vintage forum to get some ideas. With the most modern (and, yes, pricey) new steel construction you will get a bit of a lighter ultimate build and hand craftsmanship (and perhaps even custom sizing/fitting), but I have been more than adequately pleased with my carefully selected survivors in Columbus SL, SLX, etc. built up with modern pieces (in fact, I strongly prefer them to anything I could imagine ever actually purchasing...ie, not the ultra high end boutique stuff). I generally prefer the original steel forks, but you can also source a good 1" steerer (threaded or not) if you want that...they're around. Weight-wise, I don't have a steel bike for which I've tried to really be weight-conscious. I have a 1986 Bertoni Professionale built with Campagnolo Record 10 with practical Open Pro rims and a Brooks saddle that comes in a hair under 21lbs. I'm sure with other wheels/tubulars & a lighter saddle & pedals it could easily approach the weight of the bike I race with.

Of course, I don't think uber-lightweightness is one of the reasons one choses a steel bike these days. The ride is wonderful in every instance other than a sprint and I'm quite a believer that riding heavier bikes is a good thing...makes you stronger!