i ride flatland on an odyssey waltz. light and not 18.9" tt. bit more manouvarble with lighter bike - but if you ride bit of park/street too go for something built for all.
deco frames seem good, same as the new wethepeople utopia and few others.
have a gander on flatland fuel to get some ideas. most of my bike is via ebay uk from time to time. no khe baked bean tin headtube frames though.