Fisher15

If your builder used and built to code, your second floor has the same 40 lbs/sq. ft. designed load as the main floor.  The other issue is water damage, but you could control that like they do with second story or attic HVAC installations, use a drain pan.  You can make it slightly larger than the stand and paint it black.  You can glue trim over it as well.  It has a drain you will have to put through the wall, or run to a drain.  I have seen one person using a condensate pump to get any water outside.

Boought 2 40 gal breeders and a 20 gal high for $100.00