the safety squat bar is a very useful tool in the gym. It's a shame more gyms don't have them. I don't live near a commercial gym so I went out and purchased my own safety squat bar.
Like most fitness equipment there are low and high-quality bars at low and high price points. If you're looking to completely replace the standard Olympic squat for the SSB then I would probably recommend something from EliteFTS or Rogue. You'll end up spending about three to five hundred dollars.
I got my SSB from Fitness Avenue
which is a pretty generic fitness equipment store but it was < $200 CAD delivered to my house. So far it's doing a pretty good job and it's rated for 1000lbs.
I enjoy using the SSB because I have pretty poor shoulder mobility and it allows me to switch it up on days when I'm not feeling the standard squat.