New wakeboard slider! NEED HELP

[Channelwake]

Hey guys, I am building a new wakeboard slider. I know where to get all the materials besides 1. I need the floaters for the bottom of the slider. I am building according to these directions that I found on wakeboarder.com: http://www.wakeboarder.com/display.phtml?id=278. If you know where I can find the floats please let me know. Also any pointers or tips would be greatly appreciated because this is my first project! Lastly, any ideas on making it lighter would be a great help as well!

Start posting, I need some help