The G602 is very similar to the G502, which is the mouse I now use after my deathadder broke.
I have very large hands and use a palm grip, and the G502 is perfect for me, as was my deathadder.
A lot of stores (Frys, Best Buy, etc) will have mice out to try, and the G502 and G602 are very common.
As for headphones, I have a pair of Logitech G933 Artemis Spectrums, and, while they are expensive, I find them to be very nice. They do not have amazing sound quality (it's ok really), but they are durable and have a ton of features, and I have coverage of my entire house with it. Avoid the G930s, as they are built like crap.