But that's still in pitch, rather than acceleration. You would need to go from 0 to 72mph in 1 second to get 3.2g in acceleration & I'm not sure if even a jet fighter could do that.
British Aerobatic Association registered schools here:
https://www.aerobatics.org.uk/training
Ultimate Aerobatics at White Waltham are just east of Reading, so down the M4.
South West Aerobatics are based at Dunkeswell, between Taunton & Exeter.
Gloucester airfield, for Altered Attitude Aerobatics, is between Gloucester & Cheltenham.
There's also a couple of gliding clubs near Stroud that could do a trial flight with an aerobatic instructor & get 4g.
https://bggc.co.uk/
https://www.cotswoldgliding.co.uk/