Its the ATI one and well, is it a good thing? I've seen reviews saying that it overheats or has high temperatures? Would that affect the system as in would the high temperature of the graphics card burn other parts on my cpu like the processor, motherboard, hard disk? =)
Definitely a great choice. It doesn't "overheat" it just runs a little hot, but these chips were designed to run hotter than usual. I would suggest to do as I did and get a version with aftermarket cooling. My Sapphire HD 4850 Dual Slot never goes above 60 C on my Antec Nine Hundred (I live in a tropical country though, so room temperature is also considerably higher).
Aftermarket cooling is using a different cooler, purchased seperatly and installed on the graphics card instead of the stock cooler that is already installed on it when you purchased it.
Overheating=Heating over a certain point, and that point is usual when the equipment (in this case your video card) is not working within specifications (that means normally).
The HD4850 (all stock cards, not just Gigabytes) run hotter than other similar generation cards, they do run on the "hot" side, but never to the point they overheat. It seems that everyone has forgotten the GF6800 Ultra that run at 75+ idle and 110+ under load a few years ago. The HD4850 chip is designed to withstand those "high" temperatures and no it will not affect directly your CPU or any other components in your case. Just make sure you have proper air flow in your case and you will be fine.