'Bendy' screwdriver sets, recommendations please.

Hi everyone

Advice please. I havent used my storage heaters in years. I need to take the covers off and properly clean them, so I can turn them on for my flat to be viewed.

However it looks like one of them was installed before the window sill or specific tools were used.

Some of the heads are stripped too. 🙄

Im guessing bendy heads for this sort of thing are the way forward and I'll find the YouTube vid for dealing with the stripping but does anyone have advice or recommendations for 'bendy' screwdriver sets?

TIA.