I agree with Ventilator. You can't really get this done with one person at the quality you want. If you increase the budget a little bit, my team and I could get it done in that amount of time specified. But it would take fulltime work, and for only $1000, we can't really live on that between 2-3 people for a month. If you're interested though, email me surrealeric_at_gmail_com.

Edit: Also, my team works at 10% up front, 30% half way through development cycle, and the remaining 60% upon completion. That's pretty much the standard with most developers.