What do you mean by complete kit?
That link is for a complete probing head, which will need mounted in a spindle/holder.
I've got one of the earlier Deepgroove probing heads, and I can't complain about it. Very repeatable, and does what I need it to, regularly probing to better than 0.1mm accuracy. I've got it mounted on a dedicated probing machine, which there is a build thread for in the Show'n'Tell (Your Machines) board.