Low speed jerking… lift kit and mod suggestions

Kinda new to the rzrs, bought a 2013 rzr 800 50" last winter after riding quads my whole life, this was my first summer with it and really love it but now looking for a bit more so gonna start with a few mods. First and foremost my rzr jerky pretty bad under 5mph. I thought it may be a belt so checked that and everything looks fine. My cousin has a 2014 sportsman 800 and says his does the same thing it’s a Polaris thing.just doesny see. Normal to me, anyone else’s do it and anyone know if a clutch kit and rzr specific belt would help, if so any suggestions on clutch kits? Second I’m looking to do a lift kit as well and scrolling through the forms and ebay I noticed 2" seems to be the norm without extended axles and sway bars ect… but noticing the 2" kits range anywhere from $99-1500 and every one of them look different. High lifter has kits 2" kits on ebay but ones $149, the other is signature series $249, what’s the difference and anyone have any experience with the different kits and any thoughts? Along with a lift kit I will probably run a 28" wheel kit