Of those you listed, the State bikes have to be the pick... Both PureFix and AeroFix are made of Hi-Ten steel and the State bikes are chromoly... The first run of State bikes was pretty terrible (and hi-ten), but they have gotten better over time. Also, they are pretty good guys, and have good customer service... Their component prices can be okay (not mentioning the quality of them) and shipping is always free.

I have a State bike, and I do love it BUT I think there are better options out there. The Kilo TT is the popular pick on BF and can be found at http://www.bikesdirect.com/products/mercier/kilott.htm... Bikes Direct actually lists what components come on the bike, what everything is made of and the geometry. You often wont find this info with the other pop-up companies. The Kilo TT has a 1" head tube if that matters to you...

If you have any questions about State stuff let me know... but before you decide on anything, do a little more research and consider all the options, not just the ones that have all the flash...