There are many kits out there. One on this site from is fine.
Or the Taylor 2600. Bottom line it is one that uses FAS-DPD for measuring chlorine levels.
That is the one that uses the powder and drop titration.

As far as CYA goes, your judgement is correct. You should use non stabilized chlorine and raise your CYA separately. A ballpark number is a 10 to 1 ratio.
Meaning if your CYA level is 30 you will need approx 3ppm of FC
If your CYA is 60 you might need 6ppm

Rough guidelines but reasonable