Super stock springs will require new front hangers to fit and new rear shocks to accomodate the new suspension action. If you just want a slight lift and stock style springs, Espo may be the better deal leaf spring wise.
Nothing wrong with mopar bars and you can still find them at better prices than some of the competitors.
Addco, Helwig, or any other Summit, Jegs, or Ebay sway bar will probably work just fine and save a few dollars in the process. Even the rear, axle hung bars can be effective and cheaper than the frame hung style. The frame hung style does look more stock and does reduce unsprung weight, but the difference is so minor between the two that most drivers won't notice the difference.
However, the addition of a rear bar should be approached fairly cautiously and is dependant upon what your doing up front, especially if you want to use SS springs. I wouldn't add a rear bar unless you going bigger than 1" t-bars and a 1.125 front sway bar with stock rate rear springs. Throw SS springs in there and it can change the balance even further. I'd say try your chosen combination without the rear bar and if you still have some understeer, then buy and add the rear bar.