So what's the best solution for a ground on the the 2nd floor of my house?
Why do you need a ground? Until you can explain why, there is no way to answer
That's because grounds serve several purposes, and what works for one type might
not be suitable for another - or might actually be unsafe.
For example, equipment running of the standard AC power line should have a safety
ground, generally provided by the third wire on the plug (but not always.)
A ground for lightning protection requires a lot heavier wire and lower resistance than
one to prevent static buildup on the antenna.
An RF ground system to provide the other half of the circuit for an end-fed wire
antenna needn't actually be connected to earth ground at all.
Grounding a station (by whatever means) sometimes eliminates problems due to
common mode currents on the feedline, but can also increase those currents
in other situations.
My approach is not to bother with such a ground until I know what I need it for,
then design it to suit that purpose.