Moving from plastic to real

hey everyone i have a 10 gallon tank that i got my girlfriend. i made it really simple (colored gravel, plastic plants, fake ornaments) fail proof. However, i did a good job at making a childish set up look pretty good we both decided we want to go the more natural route. We have limited space on the stand. I will probably upgrade to a 15 gallon so a new tank will be used. I can set up the new tank while leaving the fish in the current one but i wont be able to fill it with water because it will have to be set up at a non permanent spot. How can i let the new tank get filled with water and be safe for my fish as quickly as possibly (cycled) and how different is the water chemistry going to be with live plants and driftwood or rocks. I know both of those can change ph but ill try to keep it minimal. Also how long can my fish remain out of there current tank... a smaller holding tank with possibly no filter... just an airstore. the dilema is that only one tank can be on the stand at a time. and one must be empty in order for it to be moved. i dont want to just take the fish out the establishd tank and throw them in a brand new tank. Will there be enough benifitial bacteria...etc