I might add to Ian's comment about Kodak being stuck with D-76 that when they chose to make a new developer intended for commercial processors (HC-110) this new developer had to duplicate as nearly as possible the results from D-76. They still couldn't get away from D-76!
This developer would also solve the OP's problem. It lasts a long time (years) and is cheap. You can use it as a one shot diluted just before use. Easy and no mixing involved.