Which Canon zoom lens to purchase, 200 , or 300?

OK chaps,
The good lady has said I can have a new lens for the festive season.
I have an old Canon 400d, with a Canon EF 24-105mm f/4L, but wanting a zoom lens.
Was thinking of:
1, Canon 70-300 IS USM ( Good all round I am gathering).
or
2, Canon EF 70-200mm f4 L USM Lens. ( I suppose better ' light quality', but not as much zoom).
I photograph all kinds of things, near, far, portrait, birds, and wanting to photograph more aircraft.
All inputs are welcome. Or additional ideas....
Thanks.

Mr PG