Welcome! I am glad you are getting a kitty (actually I am going to try to convince you to get 2 kitties, but I will wait until another time to do that)
I too use covered litter boxes but with 13 cat I scoop them 2 times a day. Fresh step probably IS the best but not all cat will accept such a strong amount of perfume in their boxes.
When I lived in a 1 BR apt. (BR,LR,KIT & Bath) I had 6 cats so there should be plenty of room.
And definitely keep the kitty insdie.