I dont know NJ gun laws 100%, but I would like correct Sgt. and state that NJ does allow pistol grips, only on pump shotguns though.
As stated on the NJSP Ch. 54 (assault weapons ban code), a semi-auto shotgun with either a magazine capacity exceeding 6 rounds, folding stock or pistol grip; or a semi auto rifle with a fixed magazine capacity exceeding 15rds...is illegal.
Im not familiar with the 930, but I do know its a semi-auto shotgun. With a fixed stock and a mag capacity less than 6rds, it should be fine.
If you have any questions, I highly suggest you call the NJSP firearms bureau. Ive consulted them when I bought my Ak clone, and they were very helpful and told me to call back if I had any problems with it.
I am a Jersey resident by the way.