Help me make a decision

at least 400w, why not?

for just one plant tho wouldnt that be a little much

1 plant? better be a feminized seed. I would hook up 3, 5gal DWC with a 15 gal res. DWC is good but if you just have the one bucket, you will have lots of problems maintaining ph. the smaller the res the harder it is to keep the ph at a steady level. 400w might be overkill but if you are just going to do one, might as well be a good,big one. I think you will be disapointed if you do not. you need enough light when groing hydro. just something to think about my friend.

Now can you lay me out a system that your talking about with the 3 dwc systems and resovoir? Im kinda unsure of how to go about constructing one of these...