We are SA citizens traveling with Etihad Airlines.
We have a 10 hour layover on our way back to SA from Thailand and I would like to book into one of the express hotels situated opposite the terminal within the airport.
Do I need a visa for this?
The only hotel for which you don't need a visa is the airport hotel.
For the hotel you are referring to, you will need a transit visa. The good news is, Etihad can arrange these for you very easily. Once you have your reservation, contact your Etihad airlines office and they will arrange for a visa for your traveling party. Make sure you contact them well in advance.