Design Arduino based Electro-Mechanical device to control small water valve

I am looking for someone to help me design an electro-mechanical device that will start and stop the flow of water, based on settings input by the user. The device will open the valve once you press the start button, and remain open for a set period of time. A small indicator light will flash, and a beep will sound once it is nearing the end of the valve open period (as set by the user). Once the time expires, the valve will close and the flow of water will cease. The device MUST be: - Built with the Arduino platform - Waterproof - Have a bright LCD screen (1"h x 2"w) minimum - Have a keypad for inputting user defined settings - Have a start button, back button, and two menu up and down buttons (for scrolling through the menus) - Must be password protected by a four digit pin to prevent someone else from making changes - Must run off (2) 9V batteries or less - Must fit inside an enclosure of approximately 4" x 4" x 4" - Enclosure has not been built, so we need the mechanics to be able to be built around an enclosure. Components should have long enough cables to help with the placement inside the enclosure. - Built for less than $75 in parts NOTES: - Arduino clones are OK, however you can keep the cost down. - Please the picture for an idea of what the device will look like. The device is being used outdoors in a farm setting, so the valve will be connected to standard household copper tubing, and must be somewhat weatherproof.