For 70kg the 101 could be a good choice as over 2 miles, the top speed can often count for more gain than you will lose from the marginally slower accel of the smaller board. Once up to speed, the lulls will effect the 101 only slightly more than 111, especially on very flat (mirror) water where the actual boards speeds will be relatively high/er, so the % of contribution to planing from apparent wind [vs actual] is higher than with slower board speeds in rougher water /same wind speed. So no real big negative to 101 there.
As long as you are OK starting from the beach (good skill and some pumping determination) you can almost cancel down the early planing advantage of 111 EXCEPT in the very most marginal conditions (and by quoting 7.2m/6.2m, this implies conditions above marginal).
Of course, if the wind holes are really bad (to the point of stalling all riders off the plane), then in that case the race will likely be won by the one who can plane (or resume planing) earliest, in which case the 111 would be a safer choice.
I have no idea about any iSonic101 for 2008 until AUG 15 but I'm sure it would be a little wider at the tail
And offer a little more light wind range/accel. But, of course, I'd only be speculating on that
Cheers ~ Ian