I'm loving your build, roadhouse. But I'm also hating it ... every time I read your posts, I end up going on Craigslist, looking for a Mini
As to the clutch, it is not a big deal. I installed the Barnett springs, but I don't think that they will significantly change the feel of your pedal. They are more needed for the clutch to deal with the extra weight of the car. The feel of the pedal can be improved by installing a spring that opposes the slave cylinder action. I've used a throttle return spring for a large diesel (heavy equipment etc.); it is long enough to mount the other end to the frame, and it is easily sourced from NAPA etc.
You will be slipping the clutch a little bit more than what one may be used to, but the clutch can take it.