As a SASS shooter, the best advice I can give about the purchase of guns is not to do so until you've attended at least one local match. Go, shoot everyone else's stuff (believe me, they'll all let you do so.....its kind of a "tradition"), then decide on what suits you based on real, "I've shot that," data. Everyone will have their own opinion, but nothing can match the information and data you'll get from shooting the pistol, etc.
The only "pre-advice" I can give on SASS rifles is this: make sure that you're rifle will hold 10 rounds. Most stages have 10 pistol (5 from each), 10 rifle and 4 shotgun. This may vary, but you don't want to be loading extra rifle rounds on the clock if there is no need to do so.
You're choices will depend on your preferences and what category/style you wish to shoot. For instance, I love the look of the Schoefield pistol, but I shoot duelist (one hand only). I can't reach the hammer with my thumb to cock it one handed, so I don't shoot that pistol.
Go to a local match, shoot every pistol that may be pleasing to you, ask tons of questions, and make your mind up from there.
Tanker6 a/k/a Chickahominy Charlie