Go short and breathable t-shirt or tank top. Unless you are trying to make weight for an event, sweating more by wearing layers of clothes is overheating your system. You may lose more WATER weight with layers but guess what, you will drink it back. The less layer makes it easier for you to burn calorie more effieceintly and effectively.

Just one thing i noticed, since you are trying to lose weight, i would ditch the gatorade. Other than that, awesome job so far, keep it up.

Go with what keeps you cooler. Granted the excess sweating is going to help you shed a little extra (water) weight, but you body is also having to shunt more and more energy to keep you cool than it would have to if you weren't wearing so many clothes. That energy that could be put forth to better use (ie. more exercise). Not to mention, it isn't comfortable swimming through all your exercises like that.

Added: I really ought to start checking how old some of these threads are before I post to them