If he does then longer shackles to space the springs away from the chassis is the easiest way but you will only get 3-4" this way. After that it's a body lift kit.
If you lift it a lot you have to start altering brake lines, stering arms etc and as the wheels get bigger you need to reduce the gear ratios especially if you want to go off road
And a role cage is a good idea if it gets top heavy.
Jason