I think flood and drain is the easiest, although I have never tried the drip system. I know that the flood and drain system requires a few less materials.
I use flood and drain and you can build a set up for like $60. However, If you are building the system to last you should spend a little more money to buy a food grade plastic tray and resevoir, because the plastic won't break down like it will in rubbermaid containers.
Anyway, you need a resevoir, a flood tray, water pump (anywhere from 50 gph to 250 gph depending on how big your tray and res are), flood and drain kit (to allow water into the tray and let it drain out), air stone, and an air pump. All this stuff can be bought at any hydro shop. I would buy almost all of it at Walmart though, except for the res and tray. You can get good ones at a hydro shop.