It looks like (from you avatar) that you are running a Canback top? If so you should be OK with your proposed setup although my rear springs did sag a bit even without the hardtop.
You certainly put a lot of thought into putting togeather a package from a variety of different suppliers. I would recommend Marlin's 4" trailflex kit if you want it all in one proven package.
![My Two Cents :twocents:](https://board.marlincrawler.com/Smileys/marlin/twocents.gif)