If you want to go el-cheapo minimalist style, get this one:
I have it, it works fine for small local trips. Bonus is that you can fold it up in the winter and roll it around on little castors to the back of the garage. It is a kit, however, and expect it to take a while to assemble. It is kind of a pain in the ass, but it is cheap. I know you get what you pay for, but it fits in my 1 car garage, fits my 13ft boat (at least good enough). There are ways to modify if you are pretty handy. It comes with stake brackets, so you could build a little deck and a box for paddle storage, etc. and then build out a larger surface on top. I just strap it to the cross members of the frame though.