Floating Plant Suggestions

Hello fishy enthusiasts!
I am on the lookout for a fairly specific floating plant that I am not sure exists - sorry! I would really like some floating cover for my gourami and after an unsuccessful go at keeping some salvinia natans (either I have too much flow or not enough plant nutrition) I would love to get a miniature lily pad type plant... Can anyone suggest a larger floating plant that they have successfully kept?
 

Thanks Richard, Fish seem really happy so I am loathed to change the flow in case they don't like it, I have the outflow pipe gently agitating the surface but it does create a very very slow whirlpool type effect so my salvinia was constantly moving round the tank. I think I will try and add some more cover underwater then.

This may be a really daft question but will an air stone be as effective as agitating the surface  Do I need to do either? Sorry newbie questions! Like you I would really like some floating plants but slowly dying ones look awful and can't be any good for tank!

I've found that the best "anchor" for floating plants is made by other plants reaching the surface. The roots of the floating plants gets tuck on the other plants and one ends up with a little island of floaters.
Personally, I think air stones are a waste of time unless you like the effect. A normal filter should circulate the water so that it all reaches the top of the tank from time to time which is itself enough to ensure gas exchange at the surface. The rippling of the surface effect is minimal, what is important is the constant circulation. A tank with a suitable sized filter would have to be grossly overstocked for the fish to be short of oxygen.