I would have to say All-City Big Block or Thunderdome too. I love them as a company and I would buy a Big Block in a heart beat if I could afford to. Also you could check out Tribe Cycles aluminum Track framesets for $359:

• Double-butted 6061 aluminum frame with a tapered headtube (1/8 - 1/2)
• Tapered carbon fork with aluminum steerer tube
• FSA Orbit headset

The Cinelli Mash Bolt 2.0 is on sale on Retrogression for $679. It's more than your budget but you know TREAT YO' SELF.