The S&W cannot be considered a target pistol. It just doesn't come near the required accuracy, trigger quality or ergonomics.

Tom, the cheapest starter is the Gamo Compact which is available with a l/h grip although you'll probably have to order it specially. The HW75 is similar but more expensive but does have an ambi grip. These are both single-stroke pneumatic pistols. If you can find a secondhand FAS6004 with a l/h grip that's also an excellent choice.
After that you're into CO2-powered guns and looking at the Rohm range where, again, a l/h grip is an option. There's also the BRNO range but I don't know how easy it is to get l/h versions.

Jonathan