The-Wolf
Ex-LFS manager/ keeper of over 30 danio species
I have a 4 foot, 75 US gallon tank with a sand substrate.
I had my clowns (6 at the time) in a 72G tank, provided you are going to upgrade in the next few years,
I can see no reason for you not to have any clowns in that tank.
I now have 10 clowns in a 100G.