Well, I vote for the rear sway bar too!! I have a C body boat....'67 Chrysler 300. I've totally rebuilt and upgraded the suspension over a period of almost 3 years. Each change brought marked handling improvements and the ride has not deteriorated (in fact it has probably improved).
To summarize, the car has a completly rebuilt suspension and steering system with:
New rear springs from ESPO
1.16" torsion bars from Just Suspension
1 1/8" front sway from Firm Feel
Tubular upper control arms (Just Suspension w/custom alignment)
Firm Feel stage 2 p/s box
New steering coupler, column support bearings
Boxed lower control arms
KYB shocks

The last changes I hemmed and hawwed about for quite a while but then decided to bite the bullet and go for "broke".

I had subframe connectors installed
7/8" rear sway from Firm Feel
Bilstein shocks sourced from FF

I will tell you this, the rear sway and Bilstein shocks made a tremendous difference. With the rear sway there is less body lean (to be expected) more precise steering (less steering input or corrections to keep intended path)
Better braking. Most of this is just from the rear sway I'm sure.

The Bilstein shocks alow the car to handle properly but still provide a remarkably smooth ride. With the KYB's the car would bottom on speed bumps and sudden road changes (crossing intersections at moderate speed). GO for IT!! You will NOT regret it!!!