As T said, there aren't any controllers that check beyond temp, pH, ORP and salinity. You won't find any that do ammonia, nitrite, nitrate, mg, ca, alk. Just not happening at least at the hobbiest level.
The Apex is a great unit. Not only is it reliable, and very versatile, but the company, Neptune, is extremely customer service oriented. You shouldn't have trouble if you need to reach them.
Best of luck,
Russ