Right now I have a regular queen-size adjustable bed. I bought it when working on the computer for hours each day caused neck pain and, honestly, I liked to watch TV in bed. When I bought it (about 7 years ago) I found that it helped acid reflux and my neck. I also bought a very good, foam mattress. I tried various beds such as Sleep Number, Temperpedic, a mattress from Germany, and many others that had guarantees. They were either to smelly, too hot, or too hard to move around in. This was all before ALS. I settled on a high-quality rubber mattress, covered in organic cotton and wool with a comfy mattress topper. This has served me well.
I'm looking ahead and believe this bed is not a long-term solution for ALS. My bed has more than the standard features in an adjustable bed but it doesn't make sense if I'm confined to it most of the time.
I've looked at all the threads on beds, asked those who have done lots of research, and came to the conclusion that 1. I'll need a hospital bed that has electric and remote control raising/lowering (elevation for my care and for transfers), sitting position, bend at knees position, reverse trendelenburg, and will accommodate my mattress of choice. I've still not made a choice on the mattress. I originally thought about the Dolphin mattress but it is VERY expensive and I can't get to a place to smell it to see if I can tolerate the odor. I plan on calling the company before I rule it out. The other type of mattress I'm considering is an alternating air mattress. There are dozens of them and I'm trying to find good quality ones.
Regarding your choice, there are longer beds available so with someone that tall and big, I would look at those options. I know the choices are overwhelming but I consider a bed one of the most important "tools" in the ALS shed. I've always wondered why people skimp on beds when they spend 1/3 of their lives in one. I would rather have a good bed and drive a junk car if I had to make a choice.
Also, as a CALS, you need to have a bed that gives you good support and good rest, too. Never underestimate the importance of taking care of yourself. It will help you and your PALS.