Question: '08 coil spring replacement for smoother ride

Hello all,
I've had my '08 TRD Sport since '07, I originally bought the sport model because I wanted better on road handling as I spend about 95% of my time on streets(the hood scoop looks great as well). I do love how it handles around corners and gives me virtually no body roll, however when it comes to any kind of bump in the road or when I go off road or hit washboards the suspension is so stiff that it will rock your fillings out. In addition to the uncomfortable ride I'm worried that the additional shock and rattling will cause premature wear or vibrate things loose.
My questions:
1. Is it simply the sport tuned eibach springs that are causing this extremely stiff ride, or can the TRD sport bilstein shocks also to blame?
2. If it is just the springs to blame, would the fix be as simple as buying the springs that were made for the TRD Off Road model oem? Or is there another option that I should be looking into?
3. If I get softer or "progressive rate" spring replacements, how much will this effect my cornering/handling on-road?

Look at her, so beautiful yet lacking in the comfort department
Any help would be appreciated, Thanks everyone!

 

Sub'd

 

What did you do to get your 3" lift? Blocks? Because otherwise you would have already swapped out the OEM suspension right?

 

Suspension is stock, the lift is from a Prolift billet aluminum spacer on top of the coils and an AAL in the rear. I didn't want to get too crazy, the tires and wheels were pretty expensive to start with and I didn't want to do any drastic changes to the suspension like the full suspension kits because I was worried that they would be too soft and spongy, so I figured I would use the spacer to retain as much stock ride as possible and start looking for a progressive rate spring to just smooth it out a little bit. I know, the full suspension lift or coil overs are the preferred method but I am looking to upgrade in a year or 2 to a different rig and like I said I was worried about my handling/on-road performance in the meantime if I went with say the OME Toytec kit that I was looking at. I don't want to completely change the ride, just smooth it out a little bit.