I always thought of the Cessna 'Aerobat' as an aeronautical oxymoron - the Chipmunk is a much better aerobatic training aeroplane.
Once you've obtained the AOPA Aerobatic Certificate, make sure that you apply to the CAA for the Part-FCL Aerobatic Rating to be included in your licence.
In addition to the Basic Aerobatic syllabus, other AOPA/BAeA aerobatics courses are available - see:
Aerobatics Course