hi all im coming back over to thailand in december for 35 nights but ill also be going to bodia for 1 of those weeks. do i bother getting visa before i leave the uk or just get it stamped in bodia.

ive heard some airlines can refuse to let you on plane if you dont have sufficent visa to start with

Yes, some airlines will refuse boarding if you don't have either a valid visa OR a confirmed outbound ticket to depart Thailand within 30 days of your arrival. I would suggest getting a single entry tourist visa (so that the airline to let you board without a departing ticket within 30 days). Use the visa to enter Thailand. Assuming you have a return ticket to the UK on your 35th day, you can return from Cambodia on a 30 day no-visa entry stamp.

If you want to take a bit of a risk and save yourself the tourist visa fee, then make your return reservation for your 28th day. The airline should then let you board your flight to Thailand with no visa. Once in Thailand, change your return flight to the 35th day and leave for Cambodia before your 30 days in Thailand are up. That's assuming, of course, that your ticket allows you to change the return date at no charge. The risk is that you can't get a seat.

thanks for advice single tourist visa it is