So hard 95a or 97 Durometer bushings will definitely solve the sloppy steering, That wil make your steering a little wider than soft bushings but I think your big problem is the sloppiness and the speed wobble. If you solve that then the added control might gve you everything you are looking for.
If your deck is worn out and has no lateral stiffness then this would also contribute to a wide turning radius and poor directonal control.
Double hung trucks would definitely give you a tighter turning radius but I’m told they also cause high speed instability. Another potential disadvantage of the double hung trucks is that the geometry would not match the rear drive assembly and that mismatch is not likely to pan out well at high speed. I have two sets of double hug trucks but I’ve been afraid to use them.
If you want a really tight turning radius and still want to keep your high speed stability then the best solution in my opinion is a long deck wiht a kick tail. The length gives you high speed stability and the kick tail gives you any turning radius you want if you have the skill to tick tack.
Thats what I did with my revel kit prototype. The results were amazing. Revel Kit + Loaded Tarib deck + 95A cone and Barrel bushings. I also moved the rear trucks forward 2 inches to create a longer kick.
I did a video on that combination.