Dang, that's quite a setup to have to deal with. Between transparent stands and that baseboard heater and a wood floor that you can't bury wires under, you're between a rock and a hard place.
PurdueRy's got some great advice. Definitely get longer cables! That will let you have more freedom with running wires. Any excess coils of wire should be strapped together and placed underneath the bottom shelves of your units to keep them out of view.
ANother option you have when running wires is to not only bundle wires together when possible... but take these new bundles and tie them to the support stands on your racks. That way, the supports "hide" the wire bundles as they run to the floor. You have enough supports on those units that you could probably hide all the wires in this manner.
Another option for collecting wires is to stuff them all into some lengths of split loom
. Then run the split loom where you need to. I have split loom in my setup to get the wires from my peripherals to the wall. It also comes in various colors to help camouflage itself better.
Lastly, find something to fill the bottom shelf on the TV stand to help hide the power strip and inevitable collection of plugs feeding into it.