It is not clear where you live and will be flying but if it is the USA and you intend to fly with AMA insurance at AMA flying fields the be aware that

A you need what is known as a turbine waiver see http://www.modelaircraft.org/files/510-d.pdf

B the AMA limit turbines to 200 mph

I appreciate your interest in wanting to build and fly such a model but you really do need to get some airtime on models that fly slower. My last turbine model was a Scale Starfighter and it could exceed 200 mph [ UK based no speed limits ] and I was flying on instinct and experience much of the time. At that sort of speed the model gets small very quickly and disorientation is a real problem.

This is a good introduction to high speed flight and is a fraction of the cost of a turbine model. Maybe your third or fourth model.

http://westonuk.co.uk/westonuk2_103.htm

Not many people get to the top levels and can fly the fast movers without planting one or two.