Alienware m17 R1 hard drive upgrade.

Hi to all. I am not tech savvy and want some help. I want to upgrade to ssd storage . My computer is running 2.9ghz processor. 32gig ram and 2 x 1Terrabyte hard drives.
1st question. Can I fit 2 x 2terrabyte ssd's giving me a total of 4 terrabytes?
Will my processor recognize it?
Can someone recommend which SSD's to buy and why?
My computer is stock standard. Nothing fiddled with. This will be it's first upgrade.
Your time to reply is appreciated