In all honesty, if you get a better frame as a whole bike, the group on that will probably be better than the Arabesque stuff. And it'll be cheaper in the long run to buy a whole bike rather than sourcing a frame and parts.

When you get spoiled by how well Suntour stuff shifts, how modern stuff shifts... and then going to Arabesque... it's infuriating. The difference in the 600 group between Arabesque and 6400 is a whole 'nother generation... Not only do you have Suntour's slant parallelogram, but the improvements that SIS brought around- and then there's the brakes... Man, 6400 brakes are fantastic.