When I used to grow macro, I just used one of
these with a warm white globe. I was having to give/throw away macro every couple of weeks as it grew.
If you want something more expensive then you could get
this.
i wouldn't put anything electrical from Kmart near my aquarium. they have extremely shoddy products. they manufacture goods to be as cheap as possible, in sweatshops, no less. I wouldn't risk it being near water.
I can't guarantee its providence at all, but I did buy an outdoor (i.e. supposedly resistant to weather) plug in Par 38 floodlight from Bunnings. I screwed it into the frame of my cabinet, which is metal. It's got a good rubber seal around the globe and has withstood the sump so far. I fear more being electrocuted by the skimmer than I do the lamp. My internet is failing tonight, sorry I can't paste the model in atm.
oh! and sorry, i did have a clip on aquarium light for the fuge but it died from being too exposed because even though it should have been fine and was sold in a pet shop, it was still shit. so go with the products that are designed to attach to houses and work in your backyard. they will do the job. if all else fails, duct tape it.