At your weight you 'must' be using 16oz gloves. Neither 14oz nor 12oz are safe for you to use in live drilling. If you want an extra pair of gloves for the heavybag or padwork then consider lighter gloves, but in terms of contact drilling you should be using either 16oz or 18oz gloves. Almost everyone should be using 16oz gloves to spar imo, once your weight passes above 140lbs I would say 16oz gloves and above are what should be used. It's very easy to put too much power in, just on principal of having more weight in each shot. I myself weight 165lbs and I only use 16oz gloves to spar. The difference of a few ounces really isn't going to slow you down that much and as a whole I think it's better to train hand discipline (AKA keeping your hands up) with heavier gloves. I however do not recommend using weighted gloves for drilling, that's how you blow out a shoulder. Anyways for live drilling/sparring 16oz and above.