Oh if you have filter media you need not worry, take a couple decorations from the tank and put them in the new one, take a sock full of substrate from the old tank and stick it in the new one. You can take some slime from the 75g filter and stick it in the new filter box to get caught on the filter pads. Also you can trim a little bit of the media, maybe some edges or corners somewhere on it that won't affect it, and put it in the tank.
You should be able to start this new tank without ever getting an ammonia/nitrite reading, just remember don't stick all the media in the new tank until you have some fish in there, as the bacteria will die without any ammonia to feed it, AND MAKE SURE TO FULLY DE-CHLORINATE THE WATER BEFORE YOU PUT ANYTHING IN AS WELL because you will kill the bacteria with the chlorine.