all those mentioned are a waste of money except for the cosmos. it is the same as dinan basically except cheaper. If you really want show or dinan points, get the dinan obviously.
You say you already have the ecis on your 325, does this mean you are deciding which to use on your 318? May as well not buy one because the power gains will be insignificant. You could try fogging the airbox of your 318 though, cheap and gives you a nice sound