The G2 is a good machine, however you're first job if you want to go to CPL H, is more likely to be an R44...
I would train on the R22 , far easier transition to the R44.
I would highly recommend
https://www.arcus-heli.com they have a G2 , R22 and R44. (based at Nottingham) about 1 hour drive from peterborough
The Exams are all achievable , but you do need guidance through them, and you be under an ATO for the exams with consolidation classes before sitting the exams ?