Hi there. It depends what you’re hoping to do in the Phi Phi islands.
If you’re mainly wanting a private boat trip where you can avoid the worst crowds at Maya Bay etc, I would actually recommend staying a couple nights in Phi Phi Don if possible, and then hiring a boat from there. It’s easy to charter a boat in Phi Phi, and this will allow you to get an early start for sightseeing all around the islands before the crowds of day trippers come from Phuket. Phi Phi has luxury hotels too like Saii and Zeavola Resort.
Otherwise, if you’re just wanting to do a day trip to Phi Phi and a convenient area to stay in Phuket nearby, then anywhere in south Phuket would work for that. Two good options in the southern part of the island are Sinae Phuket or Royal Phuket City Hotel.