Digit display

I have an Arduino uno running a program to detect the value from several sensors and relay the final numerical result to the serial port. I would like for this number to be displayed on a large dual digit seven segment or LED matrix that could be easily viewed by a forklift driver. does anyone have any good recomendations as to where i could purchase such display with 8" tall or larger digits? Also, how would the display recieve the data to display?

For that size, you may want to just buy a couple of large perfboards and solder rows of 5mm LEDs to make the segments.

You'll generally need to individually control each segment. Typically people use a lookup table to convert each digit to a series of ones and zeros corresponding to the segments that should be lit/unlit. Purchased displays or helper ICs may have simpler means of accepting data such as serial or I2C but they may not be cost effective for just two digits.

Rolling your own 2 seven-segment displays would require 14 pins, do-able on an Arduino but you'll probably want a shift register to reduce pin count. There are shift-register-like ICs designed to drive LEDs directly, but you'll need to add up the mA of the LEDs in your display to make sure you are within the specifications of the IC. If there are too many mA for a helper IC to handle, you can just use a couple of cheap simple shift registers and drive each segment with a common cheap transistor. They don't even need to be latched shift registers, as clocking out two digits will happen on the order of microseconds, far too fast for a human to see any flicker.

Can make up digit segments using 12V LED strips. Use TPIC6B595 shift register to sink current thru the segments to make them light up.
6 LEDs/segment would make ~9" digits.
writing to the shift registers is easy:

digitalWrite (outputClockPin, LOW);  // SRCK pin
digitalWrite (outputClockPin, HIGH);

fontArray = {
B00111111, // 0 high turns on a segment, BxGFEDCBA
B00000110, // 1 A
//etc. F B
} G