If you have enough code-space you could use the same PIC.
You will only need to use 1 74LS244 and four resistors.
I asume you are driving the LCD in 8-bit mode with all of the data lines connected to the same port and you probably have your LCD control lines on another port.
Using the circuit below, IC2 is a 74LS244
Edit: Schematic Removed by the Author. Responding in this thread is not worth the effort
Pins 17, 15, 13 and 11 of IC2, connect to RB0, RB1, RB2 and RB3
Pins 18, 16, 14 and 12 of IC2, connect to RB4, RB5, RB6 and RB7
Pins 1 and 19 of IC2, connect to the pin you are driving the LCD Enable line with
When you are not driving the LCD, you can scan the keypad.