Hi there, thanks for the input.
The pond liner has since been relocated. It runs up the wall about 8 inches now and I will be running more peices down and over lapping the bottom pce. It's hard to explain but when I am done the stand it's self will hold water.
The edges of the liner will be siliconed to the floor thus not allowing any water under it. I did this with my 55 and it works awesome. I designed it so that the cavity under my tank can hold more then 55 gal as I didn't want to drill a floor drain in the floor where my tank currently sits.
I have NUMEROUS plans to keep water from ever hitting the floor and if it should it will be directly into a floor drain, filter sock and back into the sump.
My 55 has been up for 4 months and I have yet to spill a single drop of water on the floor around it. Knock on wood!!
I thought about removing the 2x4 top but I already have all the lumber and it puts my counter top 3.75 inches higher then the 2x6's, giving a person a little more room for their legs under the tank and it gives me a nice straight line across the front to attach my oak trim.
I am buying a second hand tank so I am not sure where it was built or buy whom. It is being sold by another forum member.
Yes, the sump tank is in the basement below the tank. I just finished building everything done there and I couldn't be happier.