is PPV a brand, or a certain type of sway bar?
Keith is recommending you look for the sway bars from a Police Patrol Vehicle Tahoe. The PPVs are designed for high speed pursuits and have larger sway bars, beefier springs, and stiffer struts. I own a PPV and just replaced the struts. The ride is stiff for a SUV. Not as stiff as my Nissan 300zx with aftermarket coilovers but you will feel every pot hole and rut in the road. The SUV is "tossable" in the corners though.
How many miles are on your suspension? You might want to start by jacking up your truck and checking everything for play. No reason to pay for a bunch of upgrades when a loose bushing or worn tie rod might be causing your problems.
Some things to check:
-Are your wheels tight when in the air? Just a tiny bit of play in your steering rack can cause a bad "wandering" feeling on the road.
-Check your end links, steering rack and linkages, and all control arms
-Check your struts for oil leakage. If you have more than 70k miles on your struts, replacing them will probably help your ride regardless of external leaks. Avoid Monroe!
P.S. Is that a giant Crape Myrtle in your front yard? If so, incredible! Are you from DFW?