How far is Surat Thani from Phuket?

I plan on taking a night train from Bangkok to Surat Thani, then catching a bus from Surat Thani to Phuket. Does anyone know from personal experience how long the bus from Surat Thani to Phuket will be? And then how far the boat from Phuket to Phi Phi will be? Thanks for your help!