PATA is also called IDE. If you do an eBay search usually more of the drives are listed as IDE.
A modern SATA drive has a different connector and will not work.
Most of the older G3 Powerbooks, perhaps all, can only recognize up to 120gb hard drives, so don't buy one larger than that. Otherwise any IDE/PATA hd will work.
Which model Powerbook do you have? Pismo, Lombard, Wall Street, etc.?