| I do like the apexi because it doesn't matter which combo we're running we can tune to suit, we have a lot of runs on the dyno with the apexi so Thomas has a real good idea what tune to put in it, and even I had today.
A lot of people have spent a lot of hours on the flowbench trying to find out what works, its not like other heads.
I know of other Mini owners / tuners who have hit 230+whp with the stock compressor to throttle body pipe.
I think your estimate for a head (10-15) is spot on, though there are heads out there what seem to produce a lot more than this.
No new chip, your current air fuel is safe as houses. | 
