fuel cell size

Im wanting to get some opinions on a good size fuel cell for my ram. Its a daily driver and i would like a decently large capacity so i dont haev to fill alot but my other thing is that it has to be about a foot deep so i can use my stock fuel pump. I wanted to see what you guys would pick if you had to choose between a 15 that was deep enough or a 20 that would require a 3" billet adapter for my stock pump to work.