I use plumbed rack trays to water in place... not sure what size you would need, but like this..
Amazon.com
Then drill it and install this bulkhead
Amazon.com
You can shove 1/2" PVC pipe snugly into the bottom of the bulkhead, leading to the next tray. Under the bottom tray place a large container to catch drain water, or plump it to run directly into a drain.
You can see it in this pic of my grow room
[IMG]
Untitled by
Eric, on Flickr[/IMG]
If possible, water with a hose for maximum convenience. If that's not possible buy a pump sprayer and take off the nozzle. There are electric pump versions if you don't want to pump.