I've used both pink fiji and pool sand. I like the pool sand's texture, color and price so I tend ti use that. But if you like the color and look of the fiji then its up to you about the price difference. Pool filter sand is about $5 for 50lbs and so far I have only found it at home depot.
For test kits I;d recommend API liquid tests for the basics like ammonia, nitrite, nitrate and high range ph. When you want to test for calcium, magnesium and phosphates I stick with salifert or red sea has some good tests.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.