You're always going to have a res in hydro. It's what you do with it that makes the difference in styles.
A tray-over-res system of ebb n flow is the easiest to build and maintain and is also cheap. You buy components at the grow shop that will fit your space and light, and assemble them into a working system for less than the cost of a pre-fab.
Read grow logs for all sorts of system designs, and see what is working for people running differnt styles of operation.