Without going into the various varieties, as have basically been discussed:
DP RCB, which will take care of a main switch or RCD upfront and include the necessary MCB
SP SPD + MCB for the SPD
The minumum you could get away with is 4 ways for each system and depending on space depends whether you will get away with a 2 or 3 way split board (12 way in total) for HP, PV,EV or whether you need another CU or you change your house one and put you garage workshop on that or chance used F&G parts.
My preference for a garage workshop, would be to come off an appropiate size MCB in the housee and run a suitable cable to a CU in the garage woekshop.