If you positively have to get a 46 engine and Futaba radio and you don't want the Nexstar; you MUST buy plane, engine, and radio separately. Sorry but that is just the way it is.

If you have some flexibility, these are the ones I found in 5 minutes looking at www.towerhobbies.com and www.quantummodels.com
There may be many others but these were easy to find.

I know nothing about non-US mail order firms; you're on your own with that.

Flat bottom wing
Hobbico Superstar Select does not come with the 'features' the Nexstar includes; but only has a 40 engine
Thunder Tiger Easy Trainer 40T Combo; comes with .42 engine and Hitec radio (compatible with Futaba buddy box)
Thunder Tiger Easy Trainer 40T Plus Combo; same as above but covered with Ultracote rather than sticky back material

Semi symmetrical wing
Hobbico Avistar Select does not come with the 'features' the Nexztstar includes; but only has a 40 engine.
Thunder Tiger Easy Trainer 40H Combo; comes with .42 engine and Hitec radio (compatible with Futaba buddy box)
Thunder Tiger Easy Trainer 40H Plus Combo; same as above but covered with Ultracote rather than sticky back material