definitely go to a garden shop if there are any around you, if not do a ton of research on here. I just started a new lineup with dyna gro, dyna bloom, cal-mag and liquid w8 (for flower only), my plants are loving it! its always best to have lower levels accordingly when it comes to nutes. too high will burn your leaves and they will turn brown at the tips, yellow and get really crispy. Some good brands are General Hydroponics, Dyna Gro products, Fox Farms (but must be careful with burning) etc.I would recommend getting nutrients either at a hydro shop or online.
17-17-17 wouldn't be ideal for flowering.