I have no ideal on the prices, I would guess around 3 hrs labor. The only thing you will notice with the kit is the 500 rpm delay, which is what it is supose to do. After a little while you will not even notice it being there.
The one that HL sell's is the EPI kit. As far as I know there is not other kit available. The centrif clutch does not have to be pulled to install the springs. It just makes it alittle easier when it is out. All you have to do is stand the bike up on end, make sure it is clean first. pull the clutch cover off and stuff a few rags around the clutches to keep from dropping anything in the engine. remove the e-clips and plate on the centrif clutch. using a spring puller and needle nose plires to remove and install the new ones. I'm not going to lie and say it's an easy job, the new stiffer springs can be a pain to install sometimes.
The one that HL sell's is the EPI kit. As far as I know there is not other kit available. The centrif clutch does not have to be pulled to install the springs. It just makes it alittle easier when it is out. All you have to do is stand the bike up on end, make sure it is clean first. pull the clutch cover off and stuff a few rags around the clutches to keep from dropping anything in the engine. remove the e-clips and plate on the centrif clutch. using a spring puller and needle nose plires to remove and install the new ones. I'm not going to lie and say it's an easy job, the new stiffer springs can be a pain to install sometimes.