As long as I have been going to the park, SFGAm has always allowed single riders on Whizzer. Also, if you choose SFGAm, a night ride on Whizzer is HIGHLY recommended.
As for the lack of "classic" rides, the park has Whizzer, Demon, American Eagle, and Little Dipper. Additionally, the park is one of the very few that still has two Arrow Flume rides. Also, the park has a large number of classic flat rides.
If you do end up choosing SFGAm, get to the park by 9:30 and go directly to Goliath when the gates open. After Goliath, continue around the park hitting Eagle, X Flight, Raging Bull, Viper, and then cut back to Demon. Most days you should be able to make it through all of those before hitting any lines. If you visit on or before August 9th, I'd recommend you purchase a Gold or Platinum Flash Pass online in advance. After August 9th, the crowds let up a little bit and I'd say not to buy a Flash Pass in advance and see how the crowds end up being.
Superman and Goliath have Single Rider lines. For Superman, head up the Flash Pass entrance between the ride entrance and the gift shop. This one almost always results in a walk on. For Goliath, inform the employee at the entrance you are a Single Rider, you will be directed to the Flash Pass entry up to the station. There is usually a short wait, but if that line is coming down the stairs, AVOID at all cost.