Design & program a device with Keypad, Lights and Buzzer (probably Arduino)

It has been since I was a kid since I built & soldered things, but need to build 5 of these devices for a “simulation” so I’m looking for some help with the design. I do have an Arduino Leonardo, and have done some very simple (the samples) programming with it, and am wondering if this might be a way to go build these. But am flexible on another Arduino board, OR a standalone IC chip. Here is what I am trying to build (see uploaded crude diagram of my thinking on the circuit/components): PURPOSE: This is to SIMULATE the “locking” of a door, and then the “unlocking” of the door when you enter the correct 4 digit code. This does NOT control a door, just the red light, green light and buzzer. SPECIFIC REQUIREMENTS: -Keypad/IC that can be programmed with two 4 digit codes [lock and unlock] (or could be done via program if using Arduino). 4 digit code must remain when power fails. -Green light turns on when power applied and is in “ready state/disarmed”. -Entering the 4 digit LOCK code (and probably #), on the keypad “arms” the circuit. Meaning that #1. The buzzer sounds (probably in a pulsing pattern for a 5 seconds, then turns off), and then #2. The red light turns on and stays on. -When you enter the correct 4 digit UNLOCK code (and probably #), the circuit goes back to “ready state/disarmed” meaning that #1. The red light turns off, and the green light turns on. -Device now back in “ready state”, “armed” again and the cycle can start over again. -The 2-light/buzzer combo unit [that I must use] is 24VDC, so I don’t think I can run that directly from the board/IC, so will probably have to use a relay. This 24VDC 2-light/buzzer combo unit is the only part that is already determined and must be used ([login to view URL]) . All other parts are flexible. -Need to put the IC/Board/Switch in a project box. -Of course cheap, reliable, and easy for an amateur to build ;) DELIVERABLES: -diagram/schematics of a circuit/device that meets the specific requirements above. -parts list that is readily available from US suppliers (part numbers and/or URLs preferred) -Working, well documented Arduino code/program if that is used. PAYMENT MILESTONES: -50% after above deliverables are supplied, then I will order parts (for one unit) for fast shipping to test. -50% after design/device is assembled and tested.