Well if you want to keep the coils... the only thing that you can do (and im not suggesting it, im just saying it can and has been done) is to get the new UCA's from greg then have him fab you up a 1" lift coilspacer.
If you put the very small coilspacer ontop of your current strut/spring combo along with the UCA you will be getting the max amount of lift possible without doing a diff drop lift.
yeah, you can't really go much higher with AC springs without a drop diff kit. Almost anything over 3" of lift will cause angles to be too great and cause damage relatively quickly.
I have the AC Coils and Titan Bilsteins. The spring seat is about 1/2" - 3/4" higher than the OR Bilsteins, so I sit a little higher. If you switch to Titan Bilsteins, you'll have to reuse the spring seat from the OR Bilsteins, as the Titan spring seat is too wide.