If you don't want it much stiffer than your Pro-kits, just get the
standard "street" rates that GC recommends.  350/250, IIRC.  They will use
2.5" springs.  2.25" are for space-challenged apps, like tiny racecars.
        Roll bars: definitely get something in the back, I have the Shine
rear bar, PITA to install, but very nice.  I'm running the stock 20/25mm
front bar, you might decide to go bigger.  Try it first with the stock
piece.
        -Paul