You just need a marine salt mix.
You could ask a thousand people on which is best and get 1001 responses, it's a very personal preference and there have been many debates over which is "best." They all have advantages on their own, like say one may add more calc to your water than others, or somethin along those lines.
Do some research on here, I believe there was a thread here or somewhere on the net of someone who did a very in-depth testing of various salt mixes and what they had in them.
My advice is try several different ones and see how you like them