Four acts.
Yes it can, and Wizards are probably the strongest class in the game right now (in regards to Inferno difficulty). Spend 20k gold on the AH and get a complete set of gear with INT and VIT. Not either one, but both on the same item. Don't worry about those other crap stats at the moment, and don't spend more than 5K per item. If you need to, wait ten minutes and refresh, there are killer deals all the time. In Inferno your stat priorities will change (for a Wizard).
I dont use the AH personally. only trading and what I find myself