Of the ones you are considering I would choose the ebb and flow, not that any are going to do better than the other, but simply because there is less that can go wrong. The drippers will probably plug up before the first plants will mature. The bubbler system will only 'bubble' if the stone doesn't get dirty, and the water level is kept EXACTLY at the right height.
However, if you want to have each plant mature one month apart, I would not choose any of them. Consider this: say two weeks before you harvest one, that plant will be say 30" tall. So when you place a newcomer next to the 30" plant, you will have that one maybe 8" tall. Where will you set your light? You obviously will have to stay above the 30" plant, which is too high for the 8" one, so it will become very stretched reaching for the light.
To do this, you will need to have each plant in a separate pot, and place the 8" a foot higher that the 30" one so they get the same amount of light. This can be done in hydroponics .... prolly a drip system (:
I would still use the ebb and flow and forget about harvesting once a month.

spaceneedle




Quote Originally Posted by sourness
high everyone, im need to the forum but have a little growing experience (made a garden for my senior high project loolzzz) hopefully that help me a lil bit. i been reading a bit on this forum and i bough a growing book that i just started reading. i want to grow hydro but now sure what system to start with. i want to grow 4-6 plants a month a part. this are sum of the inexpensive system that i found.

1. General Hydroponics: GHBB® ECOGROWER® 17 GALLON RESERVOIR DRIP HYDROPONIC GROWING SYSTEM - 22.5 inch X 22.5 inch X 15.5 inch [706721] - Hydroponic Systems - Grow Systems - Discount Specialty Farm, Greenhouse & Garden Supply Store - Horticulture Sourc

2. Amazon.com: Hydrofarm MGSYS Hydroponic Megagarden System: Patio, Lawn & Garden

3. ...Emilys Hydroponic Garden System..NO RESERVE for sale

4. Big 6 Plant Hydroponic Drip/Bubble system for sale

feel free to post pros & cons of this systems. or add any other ones that you guys had good luck with. thank for any help