How about a 100% Merino Wool? However, you would be called upon to coordinate your own colors for the striping sequence. Fun!
I knit with NORO Silk Garden quite a lot, and it knits as a worsted weight, although it 'looks like' a DK weight in the skein.
Another idea: how about using same-qauge yarn leftovers ? Just start with a color til it runs out, and attach a new color using the "spit/splice" invisible technique, and carry on!