I need to develop a timer that starts and stops based on a certain inclination determined by an accelerometer. Any suggestions on what kind of microcontroller I should start with? I also plan on incorporating a micro vibration motor and a display into the device as well.
Look like EZ430-Chronos from Ti is suitable. Check this out.
is that programmable with arduino?
You could use a programmable accelerometer with event-output pins connected to a 555 timer.
But since you want to add more, what kind of display are you interested in? The vibration motor should be simple to control ( microcontroller output pin + bjt/fet + diode ). An MSP430 is a good 16-bit controller, but you may also do well with a PIC or AVR (arduino compatible).
To save space, you can use the same AVR processor that the arduino uses, and a custom board if you like.