I've done small scale hydroponics ( about 40 feet of tubing) and that was over 30 years ago. Yield was not great and I did not run the system for more than two years.
At the time, nutrients could be purchased at many garden / farm stores for lower prices than you will find today. Inflation is a real factor in this.
I also tried making my own manure "teas" to feed the system, but faced the need to do lots of testing to determine exact content of the liquid. Again an added expense.
I don't mean to discourage you from hydroponics but in terms of prepping, you'll need to stockpile those nutrients along with your other prepper stock (food, water, gear, etc.).
There are Many sources for hydroponic systems and supplies, it is an active business network. We have at least two stores which cater to smaller hydroponic system. One of these is just a few blocks away from us here in Reno.
Research, research, research...