There's no upgrades that make a vehicle handle better, even shocks don't necessarily make a vehicle handle better. The driver and the tuning of the vehicle are the keys to handling. The weight of the shock oil and the spring rate of the springs make more of a difference than the manufacturer of the shock itself.
Everyone (or close to it) on this forum is here to help. But finding someone to do what you're asking is unlikely. I recommend getting in touch with a distributor. Tell them your intended use, budget, goals, what you're comfortable assembling etc and have them put together a package for you. A distributor like Dave's Discount Motors, TGN, Large Scale, should be able to do that for you and give you some support after the sale as well.