To the original question Kamdavid...what fish do you intend or want in this tank? Substrate fish such as a group of Corydoras, or a group of loaches, will restrict you on the substrate options, so it is best to decide this.
Second, the Fluval Stratum is an issue. Fish that dig may have issues with this, so again depending upon the intended fish, this may or may not work.
Generally speaking, sand is a better substrate than gravel. However, if you want tyo replicate a Central American or Mexican stream, gravel up to pea grain size is authentic and very workable. But you would not have loaches or cories in such a tank. But in general terms, sand does provide an excellent plant substrate, it does look natural (aside from the afore-mentioned, almost every stream and creed in Tropical areas has a sand substrate, but never use white), and it visually makes the tank space seem larger. Not all sand is suitable, this again depends upon the intended fish.