RG
Hi Zach,
Any good quality wheel bearing grease should work fine. One of the tricks I learned for adjusting the pre-load is to have the bike OFF the centerstand. This allows the whole system to be loaded before you start tightening the slotted nut. Also, if you can have a helper hold the slotted nut from turning while you torque down the top nut, that helps.
Rick
’74 R90s
’04 R1150RT