I'll definately agree with you that 109.5" is a perfect wheel base. However, I want to move the rear axle back about 2" so when I go with larger tires im not stuffing them into the door. Also by doing this I wont have to lift the XK as much to fit a larger tire. It will be similar to the AEV Iceland Commander. Just not moving the axle back as far or going with that large of a tire.
http://www.aev-conversions.com/vehic...xk_iceland.php