gsm alarm with video surveillance

Hi,

I’m working on a project: GSM ALARM SYSTEM WITH VIDEO SURVEILLANCE.

I am also new to using arduino.

I intend using an arduino board to implement this project together with a gsm shield.

I have two problems:

first of all, i don’t know which arduino board in particular to use, whether the uno or the mega and secondly, i am almost clueless as to how

i can use a camera together with the arduino board to start recording or taking pictures as soon as the PIR detects motion. I want the arduino

to be able to make the camera start recording for a duration of about three minutes and save the data to its own storage or any other. And also, the

particular type of gsm shield to match whatever you suggest.

Your help will be very much appreciated.

Thanks.