You shouldn't encounter any problems with a leveling kit. If you use spacers, stock ride will be virtually unaffected. If you use the D25 springs, then you'll probably have a bit stiffer ride. Either way, it's up to you. Just don't forget to get extended shocks!
Beware that if you don't install an adjustable track bar, your front axle will slide toward the drivers side a small amount. I think it's 0. 11 inches per inch of lift (I believe Dieselman had posted that). The best way to fix it is to install an adjustable track bar AND a track bar drop bracket, to bring the bar parallel with the drag link. Skyjacker should be offering these items eventually, if they don't already.
I'm currently in a debate with myself over whether to go for the Skyjacker 2 inch lift, or their 4 inch lift. I only intend to run 35s, so 2 inch would be fine. But 4 inch might be good when I add a winch and bumper, whose weight is likely to compress the front end.