The reason a matching coil isn't needed is simply because the antenna losses are great enough that the match is close to 50 ohms when in resonance. In this case, most of the overall loss is in the coil as the Q is rather low as screwdriver antennas go (30 to 60 or so).
If you haven't decided on who's stake pocket mount, you might want to look at http://www.geotool.com
With respect to the BetterRF unit, just make sure you use at least 5 turns, and preferably 7 or 8 through the core.
If you want the updated installation manual for the tuner, got to my web site, and look under Antenna Controllers. There is a link to the pdf.