Havng had the 4*40, 4*60 and the Tiger 60.... If you want stability in gusty wind... get the Tiger. Its heavier and not bounced as much.

The 4*60 is heavier than the 4*40... but the effect of scale comes into play... it flies like a lighter aircraft. From experience with previous models I expected that, and added retracts mainly to bring the weight up. It still floated just like the 4*40... but the ground handling improved immensely. If you need more stability in wind... there would be no problem with just adding weight on the CG of the 4*. (vertical performance could suffer if you added a lot... but a heavilly weighted 4* is a trainer for flying warbirds.)

The Tower .75 should be PLENTY of power for the 4*60... For best results use the longest prop listed in the engine's manual as being appropriate. (it might be able to hover when your skill gets to that level.)

The Tiger's wing comming apart for transport is handy... but not that big a deal. The fuselage is almost as long as the wing. If you have room for the fuselage, the wing shouldn't be a problem on the 4*60.