As far as your questions, yes you can cycle anything regardless of the decor, however use your cycled tank to your benefit, as capslock suggested.
If you plan to have future tanks, or don't want to keep a hospital tank setup all the time, make a sponge filter, leave it in your 55 gal tank, when you start a new tank, add it to the new tank, or hospital tank, as needed. Just be sure if you use it for quarantine's that you're not re-introducing stuff to your community tank.
Sponge filters are great to increase your bio filter capacity, also in a pinch the continue to filter your water if your pump or hob goes out.