That is a decent kit but, at the end of the day, your still going to be riding on the stock springs and they are prone to sagging once you add weight to them. Also, you can't really upgrade them like you can with a coil lift either.
I would take a look at this lift:
TeraFlex JK 2.5 inch Lift Kit, W/ Shock Adapters
or with shocks
TeraFlex JK 2.5 inch Lift Kit, W/Shocks
Those are two nice starting points in the TeraFlex line that will get you a nice platform to grow on. Yes, there is nicer, more complete lifts but this is a good starting point.
Also, you mentioned 3.5". These will not get you that heigh and you will have no issues with the driveshafts needing to be replaced.
Also cheap insurance but I would throw in one of these as well:
TeraFlex JK Exhaust Spacer Kit for 2012-13 Driver and Passenger
If you have any questions or if there is anything we can do, please let us know!