David,

Your planned use of a shifter extension will work totally the opposite of the
short shift kit. You will find that the play is even more exaggerated as the
shiftknob will be traveling a greater distance with each shift.

If your goal is to simply bring the shiftknob closer at hand, then fine. The
extensions is all you need. However, if your goal is to make shifting quicker
and also lessen the apparent sloppiness of your shifter, then go short shift.

BenT Nohb