We recently put together our Peninsula 500 few days ago and placed on our living room.
We have ceramic tile floors similar situation making it a little difficult to level it and worried about cracking our tiles. So, the solution we came up is to put 3/8" of solid plywood (the good kind) from HomeDepot and we had them cut it same dimension of my tank. This thing works for me, our tank is leveled and didn't even have to use any shims. Mine didnt not come with levelers, adjustable screws at bottom of stand only.
You have option to paint to match your stand.
Hope this help or give you some ideas.