I just installed a set of Hogue grips on my MK III SS and I am very happy with them. I got the uncheckered cocobolo grips with a thumb rest. They weren't cheap at 80 bucks but are beautiful and they fit perfectly. I ordered them last Wednesday over the phone and they were delivered Friday--two days! (Hogue and I are both in California.)
Another reason I splurged on these grips is California government's continuing passage of gun restrictions. Pretty soon the only thing I will be allowed to legally possess will be the grips...not the gun...not the bullets. I'll be sitting in my chair, with just a Hogue grip in each hand, longing for the good ol' days.