Thinking outside the box, I would suggest you make your own $10 DWC setup (assuming you have a drill). Run it for a while.

Starting out small and throwing together a very basic working system is a great way to figure out what peeves and needs you want for whatever it is you will will be interested to grow, lighting situation etc.

I agree. If possible, visit a hydroponics store in person and look at the machines that they are using as displays. You can also watch a lot of them work on youtube videos. That will give you ideas for building your own.