cant remember where i got my kit from. it was either rdg tools or chronos.

it will depend on what thickness bar your planning on knurling, just make sure it can do the thickness of bar your planning on using.
it wont reduce the wobble as the clamp type can move up and down as it knurls.

really the only way to get rid of that would be to put it between the chuck and a centre in the tailstock and turn it down.
unless you can bend it back the otherway to straighten it.