I would suggest a slingshot made for paintballs, the gun thing may be cooler, but they do make noise, and if a neighbor did see you "shooting a gun at deer" out of season it may cause a bit of a fuss.
That and the slingshot would be
A. cheaper
B fun to master something new
C less range for a miss to travel ie pepper balls all over the neighbors yard, im sure they would hate for their kids to find them, if they are that close.
good luck
Dave