1 KB/s (Kilo Bytes per second) = 8 Kb/s (Kilo bits per second)
Bandwidth is usually measured in bps (bits per second).

There are no fibre optic modems. There's nothing to MOdulate/DEModulate.
These things are called adapters. Just like your network adapter. But I doubt if you can get a cheap fibre optic connection.

Aren't there any xDSL (runs on regular copper phoneline) and/or Cable (runs on regular copper cable tv connection) providers in Washington?
If you want more bandwidth, don't be stingy and shell out some cash