If it were me, I would go for a 2" rear coil to match your fronts. You will thank me later. For rear coils, Toytec has a alot of coil spring rates to choose from. For my customers, I ask them what they will be using their rigs for and what kind of weight they will have in the rig when they do go out. So most folks have at least one or two, and sometimes three passengers, a full tank of fuel, a cooler or two, maybe some lawn chairs and maybe an eazy-up deal plus whatever whatnots you may need for you trip. That my friend is a bunch of weight. The factory coils will suck to high heaven with all this cargo and therefore give you a very un happy ride. In fact you will be hitting the rear bumpstops on every little bump all the while your Icons are begging for more.
I would definitely upgrade the coil spring rate in the rear to help make at least some sort of compliant ride with all that weight. I went with the OME 896 and really like it. When fully loaded as such the 2" OME spring provides just enough for a comfortable yet stable ride. I wouldnt go any lighter than these unless its just going to be you and a very light load. The factory coils front or rear are just not up to par when it comes to off roading. Do yourself a solid and upgrade the rear coil spring height and weight rating. You will thank me in the morning. Good luck.
No matter what, you should always have at lest the toe checked after ever raising or lowering since the toe setting on our little beasts are very sensitive to changes. I went from the next to highest setting on my front Bilsteins to the highest setting and had to re set the toe. I didnt like the way it drove, so I lowered it back down and yes, had to re set the toe again. You have everything you need except the rear coils to make this thing light up...If you have the extended rear Icons, you might want to check with Metaltech as they have an extended length coil that might work better with your extended rear Icons. You are almost there my man, dont short change yourself now. Good luck!