Oh, always keep expansion in mind, and be as fluid as possible about expansion...you never know what mind-warping new module might be about to drop that'll change your whole paradigm up! And frankly, the best way to prepare for later expansion is to admit from square 1 that it's going to happen. This is why I'll often tell users that starting with a larger cab than seems necessary is a must. After you get a taste of modular work, expansion is pretty much a given as the initial build suggests possible new directions, and having the open space on hand already makes exploring those ideas very easy. If there's anything you should keep in mind, it's that; consider going with 6U x 104, or maybe even a 6U x 126 such as the cost-effective offerings from Erica. "Go big or go home" definitely applies to selecting a first case!