19lbs is not a bad weight for an aero bike. I got Samantha down to 18 lbs in climbing configuration, but I do give up aerodynamics.
To reiterate your point: Reliability is key when going lightweight. Not using the bike setup in anything but races helps, as well. 16 or 18 spoke front wheels will only hold up for timed races, not everyday training or criteriums. I used to remove the dustcaps and rebuild my hubs after every race for smoother rolling. I had a pair of brake levers that were lighter than anything available now, but since I drilled the $#@%
out of them, they did not hold up. Be sensible when going lightweight.
Conti Supersonics are the biggest waste of money. I had a pair when I strayed from the path of real tyres. See, I can speak from experience on this clincher v. tubular debate.
I have seen a very few parts that are cheaper AND lighter than some, but (with the exception of the Renn disc, which is cheaper and lighter than quite a few discs out there) usually it is either a substandard part, or reliability is severely sacrificed.
As I say: go aero, then light.