Hello, I know of a chromogenic Agar plate called "MRSA medium" that isolate only meticillin resistant staphylococci. MRSA will grow blue/light blue other staphylo, if meticillin resistant, will grow white. If MSSA no growth.
We use it to discriminate mixed Staph. population in Cystic Fibrosis spuutum samples. But I don't know how much it cost, nor either where you can get it.
Take a look in some web pages like the one from Biolife.
There are many media selective for S. aureus and other staphylococci. For S. aureus you ahve for example the Baird Parker agar additional to the media mentioned above.
For environmental sampling of staphylococci in general (CNS + S. aureus) we used contact agar plates with self generated high salt tryptic soy agar. This can be supplemented with oxacillin (5-6 mg/L) if you want to select only methicillin resistant staphylococci.