Hello Reddace,
I would use either a drip or flood and drain system for long term plants. It really depends on what particular plants. I prefer drip systems a lot because I think in general their very simple and easy to build, low cost, easy to maintain and very easy to adapt. I don't know what vegetables you plan to grow, but I made a drawing of a simple
drip system set up to grow herbs. It's nothing more than a 18 gallon storage tote for the reservoir, a plastic dish washing tub to hold the plants you can get at any Walmart. Total cost for for both would be about $10-$12. You can probably grow up to 2-4 of the
dish washing tubs full of plants with the same
18 gallon storage tote reservoir. You can use almost any materials to build it, but the idea is still the same. Depending on the water
pump you get, the pump would likely cost you between $20 and $45 and be the most expensive part. Timer about $5-$10.
If you prefer a flood and drain system, here is an example of a simple
flood and drain system I have built in the past. Again you can use almost any materials to build one, and construct it in many different ways, but the idea is always the same.