filter question

Hi guys,

    I'm helping someone set up a 55 gallon tank for plants, and I told him
that a wet/dry was overkill for that small a tank and to buy a good canister
filter. First of all, am I wrong in this presumption?  Second, can anyone
recommend a good canister filter and a place to find it fairly
inexpensively?  Please respond via private email if this is a little too