Circuit request 4 digit 7/8-segment LED display

I have a 4 digit 7-segment plus decimal point COMMON ANODE LED display. I have written persistence of vision code to drive it which works perfectly but is a bit dim as I have only a single LED lit at any moment so that I do not overload any GPIO pin being used for power. (The segments flash very quickly!)

I want to improve the circuit by adding transistors as switches on the four anodes so that I can have all 8 segments on at the same time with power from the 3.3V positive rail rather than a GPIO pin as it is working at the moment.
Video here:

Could someone suggest an appropriate Pimoroni supplied transistor (NPN?) and provide a circuit diagram showing how to connect it up to one of the anode pins?