Taking my fish to college?

I currently have a 1-inch Female Betta living in an unfiltered 2-gallon tank (I rinse the gravel every 2 to 3 weeks and change 1/4th of the water every week). This is only a temporary setup and I want to buy an aquarium to take her to college with me. I'm thinking a filtered 3 or 5 gallon tank would suffice, with a battery operated gravel siphon to clean her gravel without rinsing the entire tank. Would adding an apple snail be a good idea as well? I'm looking for the easiest solution here, thank you!