The move from a 20 gal to a 55 gal.

[Nekkoriv]

I am moving the fish from my 20 gal to my new 55 gal. I ordered the filter yesterday, and I am going to start cycling as soon as I get the fish. Because I am not keeping the 20 gal, I thought adding the gravel, filter media, water, decor, and plants from the 20 gal would basically give it enough Beneficial bacteria to hold the fish I have now (Bolivian Ram 2 inches, rainbow shark 3.25 inches, and 4 phantom tetras inch each). It really is a small bio load for a 55 gallon. I plan on adding more fish after the 5 has been set up for about a month. So I went on the internet and did some searching, and I found an article that says that if I move everything from the 20 gallon I should be good. (I'm also going to add start zyme).
I am thinking once I get the 55-70 gal filter I should be good to go. And I'll keep both filters running for about 2 weeks. Should this work? Can I really move my fish to their bigger home so soon if I do it this way? Will this be very stressful for my fish?
Thank you for your time and advice, my fish and I appreciate it greatly.

Source: Upgrading to a Larger Aquarium - The First Tank Guide - Moving Your Fish to a Healthier and Larger Home