As above, the cooling trays for laptops are pretty useless. I have a Compaq laptop, and I can get the CPU to 75-80c without much load.
For the dongle, I have one of these:
http://www.amazon.co.uk/TP-Link-TL-WN821N-300Mbps-Wireless-Adapter/dp/B00194XKXA/ref=sr_1_2?ie=UTF8&qid=1407838308&sr=8-2&keywords=tp+link+usb
I've had it for over a year so far, and hasn't once lost connection. I use my PC for gaming and youtube etc, which i know uses a fair bit of bandwidth.
Also, my router's range is a bit crap, so I bought a 5m USB extension lead so I can have the USB adapter closer to it. Plus it's much easier to fit
HTH
Dave