I would take a look at the small flood-n-drain system you have and then see what kinds of plastic containers you can find to build your own. The fittings are as little as $7 a set and I've worked with some glue trays used to put up wallpaper. They're a light plastic, but I think they're heavy enough to hold five 5" pots in a row on a level surface. Combine two of those with a large cat litter container, a pump, timer and some tubing, and you have a pair of floot and drains that hold up to 10 plants and costs about $90 total. Of course, there are still a lot of other decisions to make and for budding I used two 2' X 4' flood tables. Smaller system were used to raise the younger girls.
HK