Seismic Assualt x4
Treasure Hunt x4
No really, that's it. $10, and you can wreck someones day at a PTQ in the near future.
That's all you need. It goes off pretty consistently, often by turn 4, and almost always by turn 5.It really doesn't benefit from a sideboard. The deck is truly too simple to deal with board adjustments.
What it can deal with, is adjustments to the land base. I intended this to be an ultimate budget example, and it works pretty well with just basic lands. If you do have more resources, then go for the gusto. Honestly though, it doesn't greatly improve the consistency. Here is some things to consider;
Manlands (particularly the red one)
Valakut, the Molten Pinnacle