Thought I would add this here as I found this thread very useful when trying to look at options to replace the shift knob on my car
I did try the shift boot option but decided it wasn't for me so went for the M45 Infiniti knob on its own instead
Rather than fitting a shift boot I replaced the standard clip with one I made from a paperclip and slid a piece of 16mm i/d silicone hose over the bottom of the gear knob to finish it off , very easy fix
I'm thinking about cutting the shifter down a little now to get the gear knob 1-1.5" lower