If buying the battery on AliExp might as well get the KT controller and display as well.
Fir the battery connection the bullets can be a bit crappy and the shroud protectors eventually melt because the bullets tbh can't handle the heat.
For battery connection opt for #2 Anderson Powerpole or the XT in pic 3 or 4 but first order the controller and get the battery with the opposing correct connection.
Are you looking for all WP connectors or SM block connector's ?
I use Ofkeet with no issues.
KT Controller 36V 48V 250W 350W 500W 750W 1000W 1500W Waterproof Brushless Electric Bicycle Controller with Light Function|Electric Bicycle Accessories| - AliExpress
For fully WP connectors opt for #4 controller with the Black/Red Anderson power pole connectors and #2 on the battery pic.
From Ofkeet store select your display, an 1T5 cable and PAS with 3 pin yellow connector. For PAS we need to know which BB the bike has.
With WP connectors it is very hard to fault diagnose, so a lot of us use the SM Block connectors. It all boils down to how neat or how you hide the wires.