I am setting up a bog vivarium(much like the one in november 2003 issue if reptiles magazine)

and I have a questions

I am going to get a power compact but I am not sure how many watts-I am going to keep these plants:
sword plants(echinodorus anubias) acorus(acorus gramineus)
java moss(vesicularia dubyana) crystal wort (riccia flutians)
and duckweed(lemna minor)

how many watts do you think will be enough? and can I find this at home depot?-I bought a 32 watt Power Compact retro fit kit for my fish tank and someone told me I chould have just bought it at home depot is this true? how do I go about getting the right one?

-Matt