Volkspanzer |
Making yourself tiny, sans coffee golem, and flying would be the way to go. So a bat or a bird of some form would be your best bet, allowing you to hide easily, get better positioning, and raise your ranged attack bonus by a great deal, for those ranged touch spells.
EDIT: Depending on your DM's permissions, you may be able to qualify for the monster feat Flyby Attack, allowing you burst out of total cover, cast a standard action spell, and fly back into total cover. Whether this would be considered cheesy or not, it's not really my place to say.