The appropriate model has already been found and with the respective model the provider was always approached directly
But you are strict with the rule "first the bell, then the gift" ;-)
Are there any other advantages besides being able to water your garden with it?
For the environment, the rigole has the advantage, i.e. the precipitation buffering device. If it also stores ("cistern"), advantages for the garden owner (but also the soft water shower user - depending on what the water is used for) are added. The "cistern only" (without rigole) brings nothing for the general water management.