The main reason air chambers are a no-no, is that they water log.
If you have them in the system already, I wouldn't worry about them.
Any hardware or plumbing store should carry hammer arrestors.
I find them where they sell the copper fittings.
If you have a closed system, (check valves, PRV's) then hammer arrestors are required at all quick closing valves.
These would be
Dishwasher
Icemaker
Washer
If you're wondering about stars (***) in posts, I do block some web sites.
If you've never seen the back end stats on a board like this, you would be amazed at the number of attempts to take over and shift it into a full blown advertising medium. Sometimes 10,000 attempts per day.