I might not have needed it, but I used substantially more height when I did mine. Depending on how close to the floor you can collapse the jack under the differential, consider this:
Stock running ground clearance is 10 inches more or less. Your stock shocks have about 4.5 -5 inches of down travel at static height generally (that's my experience/measurements I'm generalizing from). You'll want another couple inches of down travel at a minimum so you can tilt the axle a little to let the stock springs drop free and position the new ones. So, call that 10+4.5+2=16.5 inches.
That's just my experience talking. If you do two wheels at a time and set the jack stands up a little further back I bet you could get away with 16 inch jack stands with no real issue. Just bear in mind that the lower your Jeep sits, the lower and closer to the ground your axle will need to drop to get the old springs out and the new ones in.