Big difference between a Pro Stock and a stock '64 Savoy. There's a reason many Super Stock cars are set up to wheelstand. They go faster when allowed to pitch rotate.

Would doing a mini tub get you the room you need? If so, you can retain the leafs by just moving them in. With the Caltracs and stuff available for leaf spring cars now, ladder bars with leafs and sliders are not seen much anymore. Ladder bars and coilovers can also be used with stock framerails.

Or are you looking at a backhalf? At that point, I would consider ladder bars (or a 4 link) and coilovers. Lots more money, work, cutting up the car, etc., than the first option.