Well doing the math..
Current setup is 17" shock length with 2" space on top. This means when the tire is all the way flexed up, the shock will want to be at about 15" in the front.
The new shocks you are looking at have a minimum of 15.4", so when you are flexed out the weight of the jeep will be on the shocks, not the bumpstops, most likely damaging them. Sure you could run them, but if you even hit a bump too hard or flex it all the way you could be looking at damaging the shocks.
I guess you could extend your bumpstops, reducing the amount of uptravel you have, making the suspension stop before the shocks bottom out. I personally would either skip the shocks and buy them with the lift or buy them now and save them.