which is the correct port to use to get a C.I.F quote from China for goods to land.

thank you

Laem Chabang is the main port of Thailand and by far the biggest. I have a business acquaintance who uses it all the time and he claims the port and the agents he uses are extremely helpful. However, on-land transport prices in Thailand may be an issue for you depending on where the ultimate destination is.

I'd suggest you contact a shipping agent before you go too far in getting a CIF quote ex China and make sure you know all there is to know about landing product in Thailand before it actually gets here - lots of potential pitfalls and the agent can also handle internal transport and customs clearance etc,. for you. You'll need an agent anyway, so best to make enquiries before you commit or pay anything.