Shrimp Filter

[karawr]

I've got a 20g with red cherry shrimp and ember tetras.

Just wondering on filtration:

I've currently got a sponge filter like this (the biggest one) and a fluval C4:

I've got a sponge on the intake of the C4 but it really cuts the flow. I was wondering if this would be better:

And do these have any benefit over the sponge filter I currently have:

Thanks.