I would avoid the 46LA. There's nothing wrong with the engine, but no, it won't power a 3-D type plane in the future.

If you want to get one engine now that you will be able to use in more advanced aircraft later, get a good 46 ball bearing engine. The 46 FX is an excellent choice, so is the new AX.

But there are many other good choices in a lower price range - The Thunder Tiger Pro 46 and Evolution 46 are both excellent engines for around $80