Power amp under development

55-0-55 will give ~+-81Vdc when fed with nominal mains voltage.
What overvoltage can occur on your mains?
in the UK we commonly use 230V transformers on 240V mains that can rise 6% to 254V.

In any case even with +10% on mains supply to nominal you can use >=100Vdc capacitors.
 
Always alright to use higher rated voltage caps.
Like 125 V in place of 100 V.
In fact most higher voltage caps are better in quality = bigger.

What we should be careful is not to use too low voltage caps, when the margin they can be destroyed is not so big.