Dell Alienware M17x Battery

Hi all
I have a two year old Dell Alienware M17x laptop. For the past couple of months, the battery has begun to seriously deteriorate in performance... If the laptop is switched off with full power, by the time I boot, only 5 minutes is now available before it turns off...
Hence, I am looking at replacing the battery. The following are my doubts
The laptop was purchased in the US. Will there be any difficulty getting replacement battery here: http://www.batterij-adaptor.com/dell-alienware-m17x-series.html ?
Should I contact Dell or will local stores have replacements?
Will it be possible to go for 9 cell batteries for improved battery life?
Can power surges affect battery life? Is it necessary to connect the power through a surge protector?
More often than not I use the laptop when connected to power, but regularly I need to work without power. Hence, I cant remove the battery as recommended by many. Is it better to have the power always on or regularly discharge the batteries?
I am thinking of getting a cooling pad to improve battery heat dissipation. I want one that is cheap (less than 1000 preferably) and effective. Please suggest brand and model along with approximate cost.

Thanks in advance