It is easier to use the internal oscillator of the PIC. Most run at 4MHz. This should be slow enough for the LCD.
Just put the data on the datalines, but be sure to observe the timing delays needed between instruction writes. See page 45 of the following datasheet:
There is no reason why you cannot wait longer than the specified wait times (eg 50ms), as well as waiting 100ms for the power supply to stabilise. I have had problems with erratic behaviour from LCD controllers, but if you observe the wait times, you can really write an LCD display routine that is bullet proof