Even though you live where it is hot (compared to here anyway), I still believe that SAE 20 is too heavy, and can make the forks harsh, espcially on compression.
Not a big deal, but I would use something like 50% SAE 10W and 50% SAE 20 for you weight and springs.
(I use 20% SAE 20 and 80% SAE 10W in mine, with Progressive Springs and my 185 lb weight on the 2nd Gen B6).