HMMMM if money is a issue an if your fixing a a saab it must be . Id just get a AR pistol an add a arm brace an not wait for the sbr BS .
now if your rich an got time an can get the signature have at it an enjoy .
id get a 300 BO upper maybe with a short barrel if it was me . more flame to scare zombies an impress ninjas LOL
Is the jeep a soft top ?? lots of commercially made lockable storage for jeeps . maybe there is a overhead counsel setup for a hard top that will fit .