Get the Sony Pulse headset, great sound for the price and great bass effects, works great windows PC's and its wireless, they look great, and it's also inside your budget.
http://www.amazon.co.uk/SONY-PULSE-Wireless-Stereo-Headset/dp/B009LGVZ9Y...
I would get a desktop if I was you, laptops are not good for gaming. The GTX 870m would be close to 750ti which is the entry level of GTX cards. The 880m would perform close to GTX 760, but not as fast. If you are planning on playing @ 768p resolution I think you will be fine, but 1080p on a...
Try this go to Google Chrome settings, (upper right corner) History. click clear browsing data, delete the following:
Browsing history
Download history
Cookies and other site and plug-in data
Cached images and files
Then Click, clear browsing data.