Hi, You can find all above items in sofitel, but their prices are very high. I suggest try purchasing them online from Amazon them ship these item here using Aramex. Otherewise you will be robbed at sofitel.
Just note the prices of above item at Amazon then take a look around at sofitel, you will know the difference.
But, unfortunately, sofitel is the only location here in qatar where you can go for computer parts, as far as i know.
If you can shop online for computer parts. Cheers hope this helps you.