The airport trains run until midnight.
By the way I have just looked on the website for the train times and something aint right.
The site only shows 2 types of train. Red and Blue. There is a third Yellow. I know because I have caught it.
It also shows the Express train (red) terminating at Makkasan not Phraya Thai. That is also wrong. Again I have caught the Express train to Phraya Thai.
So, either the web site is wrong or they have significantly altered the service since I last used it at Christmas. I will check that out next week.
PS. I have used Pattaya Limo with no problem except on my last visit when they let me down. Keep the number to hand. I was on time. When I called they told me their driver was in traffic 15 minutes away. Perhaps he was. I didn't wait to find out. Lots of other options about.
Life is too short to drink cheap beer