Not knowing what your stock rods and crank consist of, which may be a cast crank and 3/8" rods regardless I would definitely say do a full upgrade on the rotating assembly if you plan on using nitrous.
And there is barely much of a price difference if you go with a stroker kit ( 489 or 496) and by the time you pay to have your stock rods reconditioned and have upgraded rod bolts installed, crank turned, buy new forged pistons,rings etc. and then get everything balanced you would be better off just buying a forged balanced rotating assembly from Summit Racing, Jegs or Ebay, etc.
As far as Skip White Performance they have a good reputation and high ratings and I do think they have the most affordable and complete kits out there, I know most of their kits use a Scat 9000 crank and they use Probe FPS pistons and the assemblies are balanced on a Hines balancer that is only a couple of years old, when it comes time for my next project SBC build I will get a kit from them.
Ebay can be your friend you just have to shop around and check ratings and reviews from places you are considering buying from.