As far as gambits vs the Dutch goes the most reputable is 1.d4 f5 2.e4. There is also 1.d4 f5 2.g4 but it seems easier to defend against, so I would concentrate on the first.
1.c4 you don't need to play 2.d4 making it a dutch, and 1.c4 doesn't lend itself to gambit play as easy as 1.d4 or 1.e4 as it is inherently a more positional approach to the opening. d4/e4 openings grab space in the centre, which improves gambit-ability.
I was wondering if there was an aggressive gambit white may use after 1.c4 f5. I have tried some ideas with e3, h3 and g4 gambits but am not sure of their soundness.
Doe anyone know of any?