Good 2nd planes:

Sig Four Star 40
Great Planes Super Sporster 40
SIG Something extra (if you keep it on low rates for the first few flights)
Hangar 9 Twist (Also if you keep the rate on very low, this was my second plane but it is more for 3d flying but does well for sport flying)

and a host of others

In all of the above I would really recommned the Four Star 40. You can transfer all of the stuff from the alpha right into it any one of the above