1

Can't be done - you'll have a connection in the dark at the start or the end.

Bus from Kan to Ratchaburi, Nakhon Pathom or Petchaburi, connect with a bus or train, bus again at other end to Phuket or Krabi, then ferry from either. Most trains are overnight, so you'll be at the far end during daylight, but may not make the afternoon sailing to PP. Catch the one day train or bus and you'll arrive at night and need to stay over at ST. It's one or the other, you can't have both - unless you fly, and that doesn't come into your "cheaper the better" requirement. It's a far longer journey than the daylight lasts!

2

Thank you! Sorry, I should have mentioned that I don't mind staying the night somewhere; even though it adds a bit to the cost it will be cool to see a new place on the way! Thanks again.