You will be hard pressed to find a good-riding 4-4.5" lift for a YJ. The inherent increased arch in the springs will make the ride harsher that stock springs every time. You can control some of that by getting high quality shocks to help out. If you are looking at doing SOA at any point, just save up your money a little longer, and do it right the first time. You will be rebuying a lot of parts to do the SOA conversion in the future, unless you want to end up with 11-12" of total lift by reusing your 4" lift springs.
Any reason that you decided not to go SOA?