Be careful when taking the 61W Apple adapter USB-C PD route. USB-C PD implementation is still a bit of a mess. 61W might sound sufficient but those Apple chargers can do weird things with foreign devices.
GTrusted has tested many products including the 26800 Anker power bank. The Anker power bank didn't charge at full speed with either the
29W Apple USB-C PD charger or the
60W Google USB-C PD charger.
I'm also in the power bank market and debating whether or not to switch to USB-C PD or temporarily go with QuickCharge until USB-C PD can sort out their PD.