Hi ,..I am building my own design ..and with a nostalgic look,..it is a high wing tail dragger,..3 place STOL ..I'm not looking for the same speeds you are which makes my venture a little easier,..I should have a 130 mph cruise when I'm done on 140 hp,.. and an airframe that will carry twice it's weight,..
I am an engineer but not aeronautical as degree's go,.. but from my own experiences ,..this being my 15th build,..
I've learned that the only stop sign's that pop up are the ones that you plant yourself,.. if you haven't quite got that warm and fuzzy feeling about any concept of the design ..build a model ,..scaled down, in every aspect including HP to the "T",..if it's not in your forte,.. find someone who is into building new concept models of your design,.. it's the safest ..cheapest approach without investing years of time and efforts into a project that doesn't meet your goal,..choose an existing airfoil since your looking for higher speeds,..it will save you allot of testing to find it's" no go envelope"
The new group that took over the kitfox lite is building their wings all composite,..so are the cubs now,.. I have only worked on one composite design of a bi plane prototype ,..and it is tedious building from the outside in,..one mis thought stage ..and your back to square one,..my preference is 6061 and 4130,..but that is only because I have too much old school back ground to get all warm about composites,..
one thing to consider with composites ..and the fact that they are lighter ..at the speeds your considering ,..lighter is not always good,..just for giggles take notes of the weights of aircraft that are existing that can travel the speeds your looking at that are close to your design,..you might end up with a really short wing to get the equivelant performance.
just my 2.5 cents worth