Get the XL twin beds or you will have uncomfortable guests. I have one of my rooms set up this way. I have the twin bed frames and the "doubler" came from Innstyle. It's a sherpa pad with a strap that goes around the two mattresses.
I keep twin mattress pads on the beds, add the doubler and...
We have a coffee bar that is set up the night before. Early risers, "Push the Button." We have a small fridge under the bar for water, half and half and juice. There is a "one cup" maker there at all times for those who want tea, hot chocolate and a coffee single.
The only room that gets coffee...