Hmm... perhaps if we limited the use of the stone to non-economic purposes? I mean, stone walls are something farmers have been using for years, because when you till a field, you get tons, and tons, and tons of rocks. Since that doesn't happen in DF, we should be allowed to simulate it. On the other hand, they shouldn't be processed into blocks, because with the harvest in motion, who can spare the time? Even if they're only used as the ground floor walls of houses.
I'd also suggest embarking over a partial aquifer, so that we can drive a well.