Congrat's on your purchase Bajacat,..I know your going to love your kitfox once it's done and you enjoy the fruits of your labor
as for engine choice ,..as other's have mentioned you have time to look around a bit ..and sometimes you can get a good deal on a 912,.
didn't mean to change the topic of motor choice to auto/motorcycle conversions talking about the suzuki,.but I am also looking elsewhere besides the rotax line,..and my choice ,..which I know some will dispute,..is the 2009 Ford 2.0 EFI DOHC in line 4 cylinder which pumps 140 HP out of 211 lbs of engine,..definately ,.in my opinion too heavy for a model 4 ,..but a model 7 ..I think it would work,..not pushing it on anyone to do the same in engine choice,.. the kitfox aircraft being experimental itself,..many GA pilot's would say the same about choosing an experimental over a GA plane,..versus engine choice on an experimental,..stick with what works,..if all pilots had done this ,..experimental aircraft would not exist in the civilian populace but rather would be a military nomenclature alone.
It's part of what makes experimental aircraft so appealing to many ,.the choices that are allowed in construction and power configurations.
When rotax first entered the experimental AC line of options for engine choice ..I'm sure many said the same thing about them ,..stick with what works ,..don't spend your money on a new concept,..
A funny analogy,..the roads were just repaved locally here ,,there was ton's of aggrigate left over from doing this ..it was free to the public,..no one wanted it
,..so an engineer on the project said ,..put a price tag on it~! ,..$50.00 a load,..it went so fast that now ,..it cost's $350.00 a load for the same product and people are paying it,.. no one wanted when it was free.

Chase