microcontrollore watt
You have to chose uC with LCD driver this is very important, beacuse dynamic LCD is more cheaper than static. MSP430 is great solutions. Low power, JTAG (on chip debugging), easy to buy, free IDE (for assembler, C to 2k), you need only watch crystal (32768) cause FLL( great stuff beacuse you can swich speed of uC to 7MHz). Code examples.... For power mesurement is 2 solutions.
1. ADE7753 from analog, or SAMES (expensive)
2. Take voltage and current (from precision resistor ) with A/D and multiply it in time.