RE: Which iSonic (94 or 101)
Q1="What isonic proto were you using when you when you cracked a 42 knot average on the gps-speedsurfing site".
A1= The session of Feb 23, 2006 (iSonic X - as it was unnamed at that time) was the 46.5 proto, that exact proto was UPS'd to BKK, cosmetically repaired and then used to master iS50 2007).
BTW, the fin in that session also is the proto for the Drake Speed 230.
Q2 ="Which isonic would marry well with the sonic 100 as a high wind change down?"
A2= Really depends on the intended usage for the hi wind changedown. If it's open water slalom racing or hi wind blasting in anything other than very flat water (rare, unless you're on a speedstrip), the iS87 is the "S100 changedown" choice for sure.
There is definite performance merit in not going too small for hi wind/extreme wind open water board size if you need to deal with significant/confused/harsh chop at speed.
If you wanted to go from S100 slalom race/slalom blast to (more) true pure speed conditions (and ride style), iS50 is possible but there is minimal practical overlap. (how much depends on the rider's ability to get the iS50 going early - or not- and that can also be influenced by "quality" of conditions and/or location as well as rider variables weight/skill/experience/attitude/etc.
Hope that all makes sense ?
Let us know if you'd like more info/detail etc.
Cheers ~ Ian