I have an Alero IRS swap on my Cavalier... and the rear bar from PFYC.com is much stiffer than the stock one was
It's awesome!
I also have an Eibach front bar (26mm) and it's hardcore... the car rides like it's on rails! I don't know exactly what's involved on an N-body front bar install, but if it's like a Cavalier, you drop the subframe to do it.... so, you may as well upgrade everything there while you're at it..
I did the 99 aluminum control arm swap, Prothane poly bushings in them.. plus C-body (12") front brake swap.. along with the big sway bar and Poly bushings there too..