stock FJ40 = 90"
I've got mine stretched to just shy of 100"...about 99.5 or so....with the weight balance, it's been a good compromise for the boulder gardens I love to wheel and the hillclimbs/dropoffs. 23" at the skid plate, under 7' at the cage peak.
Unfortunately, as you know, there is no set perfect wheelbase, only a series of compromises. IMO, 106 is pretty long....if I were building from scratch today I'd likely end up in the 102-104 area. There's a little to be said about the look of the setup as there is about the function, especially if you attempt to retain a full body.
It really is amazing what another 1-2" changes when it comes to wheelbase....I've had 90, 91.5 (redrilled rear perch), 93.5 (reversed rear), 97 (reversed front and rear), 99 (reversed front and rear, redrilled front perch), 100 (redrilled front perch, reversed front, linked rear), and now 99.5 (rear axle change, smaller tube diameter, pushed it ahead .5")....