Dick,

sorry i'm just nitpicking here,

but what youre forgetting dick is that static thrust is very different to thrust in flight. youve got a lot of aerodynamic drag from the large controls and the thick wing e.t.c.

example
Some people get 9-10lbs static out of the irvine 53 but theres no way it'll climb a 7lb model out of a hover with any authority.

iF youre looking at static thrust to see what is suitable for a 3d plane then the thrust produced should be at least 50% more than the weight of the plane, if not more.

IMO the only way to choose a suitable engine is to find out what others recommend or just use your judgment, trying to keep it light as possible