Your foundations are Calcium, Magnesium, Iodide, Strontium, and buffer. I would add trace elements only with a heavy stockoad. As far as who makes them, I use Seachem, but that doesn't mean you can't do well with other companies. I would avoid 'miracle products' until you learn more about how these supplements work. Start with maintaining these water parameters to get a good foundation for maintaining water quality.
Specific Gravity: 1.025
Magnesium: 1200-1300ppm
Calcium: 400-450ppm
KH: 10-12 degrees KH
Iodine: 0.03mg/L
Strontium: 8ppm
Nitrate: <25mg/L
Phosphates: 0ppm
Some notes: I wouldn't bother testing iodine or strontium yet. Find a LFS that's really good with water testing to teach you, then get the test yourself.
Some basic rules:
Don't dose buffer with calcium and buffer or magnesium and buffer. I dose them on opposite days. Set yourself up a dosing/water change schedule.
There are really too many answers for your question, but this is a good start. Feel free ask more questions so I can help more.