First of all, go with the Ruger. These single action revolvers are great shooters and are top notch quality.
Next, the recoil is subjective to each shooter but most find the 45LC and 357 to have a sharper recoil than the 45ACP, however the design of the SAA is designed to "roll" with the recoil rather than push or slam in your hand. Go visit an Action Shoot, these guys will give you more information about the sport than you will ever think to ask. Most will even be glad to allow you to shoot their pride and joy when you show an interest in joining in your new interest