Wasabi and Samourai are the respective clients.

WabiSabi and Whirlpool are their respective implementations. Mutiple clients can use the same implementation - Wasabi, BTCPay, and soon Trezor all use the WabiSabi protocol, while Samourai and Sparrow use the whirlpool implementation.

Your problem of pool sizes and postmix spending are both solved by WabiSabi since all of your inputs will gain privacy without leaving change, and postmix transactions using coinjoined inputs are not required to pay coordinator fees to make your change private again.