I prefer Mercury Browser. You can set gestures to page forward and back rather than tab back and forth. There is no default font size for every page, but for pages you visit often you can set a default easily enough. I sent feedback to Apple requesting they allow font increases and page swipes. One can always hope.
Looks like Mercury browser fixed their font size issue with their recent update. I like the look of Mercury better then Perfect Browser, so now Merury is my go to browser on the mini.