Need rear spring theory verification

[MJ'sBlkBII]

I hope I can explain this well enough...
I am wanting to replace the stock rear leafs in the BII to something that will give it less deflection to the outside rear corner thus helping to keep the front end from jacking and reducing body roll. At least this is my theory of what it will do. Will this work? My truck is mostly street, except a few dirt roads and pastures so I want to give it "decent" road manners. I belive the truck is completely stock/original and if I tried I could do a 3 wheel stand (yes, swaybars are installed). Shocks are first order of business but I want to get just enough lift (maybe 1 1/2") to get the fenders off the tires in turns.
I am thinking about these, just worry it might be to stiff with the listed capacity. Then there are these which will be a bit softer and still decent capacity. Will it still be stiff enough to keep down deflection/jacking?
Let me know what y'all think or any other ideas I'm missing. Thanks!