I actually saw a set of ground force drop shackles HERE for sale today on craigslist for $55 that i could use as a temporary fix for the rear at least. But I'm not sure if they are crap or not.
If I was you I would wait until you have the whole kit and have it all done at once. Dropping the rear 2" and getting rid of the rake would look good. But it wouldn't be worth the installation for a temporary fix till you get the whole kit. Cause hangers and shackles ain't easy to do. It requires cutting and all kinds of stuff. And I doubt your gonna do this yourself right? Professional installation ain't cheap either.
I would be doing it myself at a shop. My buddy works in his brothers shop and offered me the space and help if i ever needed it. I read/was told t the shackles were a quick install? they are the reason i was considering at least getting rid of the rake for now.
If you are doing it yourself then go for it girl. The guys that did mine, it took them all day to do. Just a quick tip, take the bed off to work on the hangers and shackles. Its much easier.