Yeah they may not allow extra sealants on a new floor for warranty purposes.
I found the part I was looking for. It is a bit pricey ($200) but it can hold 80 gallons safely. They are made for Haz-mat spill control of toxic cemicals and such but you can use them for practical purposes too. In fact, with a little patience (and a lot of boredom to fuel you!) you can browse all through the site as they have some
awesome accessories that can be used for aquariums.
This is a laboratory supply company so you can imagine they have everything from spill control products, to testing equipment (test for evey chemical in your tank!), to gas masks, to medical kits and MSDS kits.
Here is the link to the Berm/Mat spill control. (It looks kind of unappealing, but with some creative decoration you can make it work for your home. If anything it will give you a better idea of what you are looking for.)
Link:
ENPAC CORPORATION Yellow Jacket Berms - Lab Safety Supply
And here is a link to the home page for all you backstage onlookers who are interested.
Link:
Lab Safety Supply: Material Handling, Industrial Supply, Respirators, Safety Glasses and More!
HTH,
Aaron