You may be able to extend it with the help of some logic buffer ICs... I used these chips to extend a "pseudo serial" interface for my carPC. I designed an interface to drive a 40x4 LCD and handle a keypad with only 5 wires, and was having trouble with the cable distance. I added a buffer chip at both ends and it worked fine after that.
LCDs are digital and sensitive to interference. You should be able to use TTL chips. 74244 or 74245. I believe "ACT" is a suffix for the high speed version. You should be able to sample these ICs from National or Motorola for free.