Im actually in a similar spot right now. I do however, have my permit. A week from today I will be taking the BRC (basic rider course). It's offered by the MSF or motorcycle safety foundation, and in most states, succesful completion of the in class and on bike tests results in a full licence being awarded (basically it covers the road test).
As mentioned smaller engine sizes are much better introductions. I've got a kawasaki ninja 250 that i've been on twice now (its my neighbors, but soon to be mine). They run around 3K new. Used values are between 2000 and 2500, so dont think of it as a total loss if you get one and sell it within a short period of time.
From what i've heard and what I'm learning, the experience of learning how to manuever a smaller bike with less acceleration is the best way to be able to get out of hairy situations with larger bikes.
Read about the MSF classes, and remember a used 250 class bike is a great starter. Everyone falls, everyone drops a bike, and there's a learning curve. Would you rather experience those on a $2500 bike with lower speed capability, or drop a $9500+ machine that weighs more, while running 0 to 60 in 3 seconds, falling back because you hit the throttle too firmly