I am just about to place an order for a GH3. I have no lens whatsoever (just sold my HMC-150). Should I buy one of the Panasonic kit lens? My principal use will be for video (weddings etc). What is the trade off of using another brand? Will it affect the auto-focus speed and accuracy? What would you suggest as a beginner's lens? My budget is 3 000$ including the body and extra battery. Thanks!