Need help, which battery to get.

Hi folks, total noob here. I am starting my first ever conversion with an old Piaggio Super Bravo moped. I bought a Kunray 60v 2000w motorkit on Ali and I am a bit confused what battery to buy. The controller is 48-60v rated current 45A.
The motor is rated voltage 60v and rated current 33A.
I was thinking of buying a battery 60v 20ah 50A bms. Or could I also go with 48v or 52v?

See if this helps:
https://ebikes.ca/learn/batteries.html

There is a section there titled "How do I choose a pack?"

Super Bravo controller and motor.

Skickat från min XQ-BQ52 via Tapatalk

Question: Controller 48-60v, motor 60v. Can motor run on 48v or52v?

Question: Controller 45A, Motor 33A. If 60v battery will it be 60 x 45=2700w or 60 x 33= 1980w?

Skickat från min XQ-BQ52 via Tapatalk

I like higher voltage more reserve speed if needed.