Just the air ride seat that came with the tractor.
The company is also installing
Bose Ride seats in all new trucks as well. I personally can't stand them. Most uncomfortable seat Ive ever had the displeasure of sitting in.
And yes, you can get all kinds of stuff inside that cab, especially if you have a large sleeper. Microwaves, mini cooktops, refridgerators, televisions, etc. Since I'm in a day cab (no sleeper), I try to put as little in the cab as possible. So I have my phone, stereo (gotta have my books) and cold (or hot) drink. That's all I really need for the day.