Hi Dalint,
There are a number of factors to consider when it comes to your applications, but you seem to be focused on the "speed" of the process and that could be a problematic way of looking at all of this.
The application process to get into most Business Schools is remarkably competitive, so "rushing" to make a deadline is probably NOT going to allow you to put together the strongest application possible. Since the deadlines you listed are just over a month away, you'd have to study for (and take) the GMAT, score at an acceptable level and work on applications all at the same time. This is in addition to everything else that you might have going on (work, family, holidays, etc.). You have to remember the REAL goal - to get into your first choice Business School. Every "step" in this process should be done to forward THAT goal. Right now, your goal is to meet a deadline.
You might want to consider pushing your applications back a Round so that you'll have more time to work on everything. If might be that you would score higher on the GRE, but with this current timeline, it doesn't sound like you have enough time to figure that out. Most Test Takers spend 3 months (or more) on their studies to hit their respective "peak" scores. If you're looking to improve your chances at performing at a high level on Test Day, you're likely going to need more time than you've currently allotted.
GMAT assassins aren't born, they're made,
Rich