Can I make single re-entry at suvarnabhumi airport now and what documents I need? Thanks!

Believe only thing required is your passport as service includes photo/paperwork/copies for the additional price required at airport.

Remember, you must check in with the airline first before you can apply for the re-entry permit.

As a rule of thumb, you have all of the documents required for a re-entry permit obtained at the airport if you make it to their desk and have the cash to pay for it. That means you will have already checked-in for your flight and made it through the first security checkpoint with your boarding pass and passport. You will be in the area between the security checkpoint and passport control. Instead of following the masses to get in line for passport control, you go to the desk and give them the money. They will take care of the rest including escorting you to their own passport control counter to stamp you out of Thailand after your re-entry permit has been issued.

If you make it that far, you are good to go!