It depends what look you want. Big LCD-display aren't that common and might get expensive fast, the 7-Segment LEDs are brighter and can be strung to match any length you want at the cost of more circuitry.
If you go the LED way, you definitely want to drive your LEDs with a serial interface. That can be easily achieved by using one serial to prallel converter like the 74hc595, all of them chained so that you'll just need 3 pins to drive the all. As an alternative, you might use some dedicated 7-segment decoders. Those are probably about the same price. Look for "Arduino 74hc595" or "Arduino shiftout" for examples how to wire that up and drive it. It's a very common circuit. As an alternative, you might go for a ready made serial display with multiple digits.