Im going to put a companion with my oscar?

the cycled water from the 30g shes in now will be transfered with the 100g filter to my 75g so we dont have to cycle it it will take longer but its the best option and i was wondering could i put silver dollars in with her when everything is done or maybe some jack dempseys or convicts? and space is not an issue the tank is going to be like a mansion to her :) it is wayyyyy big enough for 14 inches of her when shes bigger AT THE MOMENT SHE IS 6 inches