Your welcome!  I'm afraid that short of calling the companies and being very persistent, you really can't be sure. The best thing to do is find reputable doctors who use companies with a long history of providing good products and trust them to do a good job. See my tips on how to find a good doctor and my regional guide to excellent cosmetic dermatologists. 

 pH generally isn't an issue with microdermabrasion unless an infusion system is used with a glycolic solution.  Also, I like the peel systems that are self neutralizing - usually BHA peels because it eliminates operator error (leaving it on too long).  Look at the SkinMedica peel system which offers 3 different levels of BHA peel (available with your doctor).  Their products are well formulated. 

Almost more important though is sticking to a schedule and having realistic expectations.  Peels are good for surface issues like blackheads, some pigment problems or to refresh the skin but won't make a difference in most wrinkles or generate any new deep collagen.  Occasionally they can make pigment problems worse!  Expect to do at least 2 or 3 before drawing any conclusions about their results for you.     Dr. I