slider plans, help please!

[wakeboarder_124]

I really want to build a slider. This slider should be good for all ranges of sliders but especially beginner/intermediate since a lot of my friends that will be riding it, this will be their first one.. i was thinking something like a fun box or flatbar. Something simple but can still have fun on it. I dont really have a budget but the cheaper the better. Any tips or ideas would be helpful. I am going into this very opened minded. I would like it to be fairly easy to move b/c this isnt on a private lake so i will need to be able to pull it closer to shore when we are done with it. we wont need to take it out everytime just close enough so people dont hit it. so a portable floating slider would be the best.