Good luck with that for a Hager RCBO. Current price for a domestic Hager RCBO would be over £35 from us.
Also if you are intending to add an EV chargepoint to this then you are ignoring the fact that each EV chargepoint must have its own dedicated RCBO which breaks all live conductors, which a typical UK-style single module Hager RCBO wouldn't achieve.
Out of interest - who is 'us'.
Is this the wrong RCBO ? Hager ADA332G 32a 30ma RCBO - https://www.edwardes.co.uk/products/hager-ada332g-32a-30ma-b-curve-rcbo-type-a-ac-and-pulsating-dc-sensitive-?gclid=CjwKCAiAk--dBhABEiwAchIwkZZ0mEjx0iIVv-zzqWULFu3km1cWGJO27E0qIJujj3vWNowd_8gBGBoCS2gQAvD_BwE
In any event I need to find a decent spark, to go further.