How bad do skyjackers sag? and a lift Q

Hey guys i have a 98 2 door with a skyjacker 3.5 on it thats about 4 years old. do you guys know if those sag pretty bad after so manny years. ive been away from the xj for at least two and a halph years with being in the army and all so i wasnt able to really able to monitor it verry well. So on to my real Q i want to lift it up about another inch so do u guys think i should grab a new pair of 4.5 leaf springs and coil spacers or just a pair of drop shackles? im not trying to spend to much but i want to do it right what do u all think?

any help would be awesome. thx guys

Go with the leafs...shackles make it sag faster