Esata is external, sata is internal. This is probably the information that you want.
Dis is the nfo you prolly don' want... yur mobo is crap. yur NB fan will die, and you prolly won' notice, so yu need a new mobo.
OK, if your MB has lasted a good while, then all's well. You can either use the esata option, or use a usb external drive in an enclosure. Personally, I'd use the latter as it will be far more portable, but the xfer rates will be quite a bit slower. One can buy a drive pre-installed in an enclosure for either option, or get an enclosure and install the drive of their choice. Pre-installed drives come with software suites, which may / may not be useful to you.
The fan he was talking about is on your motherboard. The Northbridge (NB) is a vital component to your mobo. I would recommend to buy a fanless zalman cooler from newegg and install that no matter what.
Also, with hard drives having disks they are constantly spinning and will be generating heat no mater what. Yes, they do tend to heat up more with more read/writes, but I have a triciary drive that has only vids on it and it is 10 degrees warmer than my main.
What kind of overheating are you worried about? To give you a idea, in my main rig I have 4 HD 2 seagates 320's, WD 500, and a Samsung 750, a 3800 X2 OCed to 2.5 ghz, a OCed 7800GT, and to cool it all I have two 120mm vans in front and one in the back and I don't have a problem at all. I also multitask like ****.