Acer Aspire 5740 models, how to choose?

Hi all,

I am planning to purchase a new laptop, basically for home use, with a fair bit of gaming thrown in.

After going through several threads and doing a fair bit of research I am quite sold on the Acer Aspire 5740 line, one good example is: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Genuine Windows® 7 Home Premium ; 64-bit version; Intel® Core™ i5-430M Processor (3MB L2 cache, 2.26GHz); 4GB (2/2) DDR3 1066 SDRAM; 500GB hard drive; integrated Super-Multi drive; 5-in-1 card reader; Acer® CineCrystal 15.6" (1366 x 768) TFT display; ATI Radeon™ HD 5650 graphics; 802.11b/g/n WLAN, gigabit LAN, V.92 modem, webcam; one-year limited warranty

However, as I am living in China, I have been looking for ways to get it in the local market in Shanghai (or even Hong Kong), and I have seen that the 5740 line has several configurations to choose from.

So, my question is the following:

-Is it worth it to upgrade the CPU to any of these models?

i5 520M
i5 540M
i7 620M

I know that the Acer site in the US does not give such option, but the Chinese site says models with those are available here. Please bear in mind that price, noise and heat are definitely important for me, but power consumption is not. So, how much should the upgrade add to the price? Is it going to get hotter/noisier? Are there going to be other issues?

Thank you all in advance!