It is a visonic powermax pro. When I bought mine, it came with the gsm and internet module already installed. Now it appears they are selling it in a different package where you need to buy the internet module separately, so you would need these two items to get started:
http://www.aartech.ca/0-101360-vison...-211g-gsm.html
http://www.aartech.ca/9-101070-visonic-powerlink-2.html
I also added a couple extra wireless motion detectors, an additional keypad to disarm it when I come home, a wireless outdoor siren, and 2 keyfobs that I can use to arm and disarm the system. you can add as much crap as you want, including smoke and water detectors, etc.
It is a good idea to install the main unit someplace secure (I put mine in a locked closet), which is also where I moved my router and modem so thieves can't just start unplugging shit.
You can get a lot better systems (Elk M1 Gold is amazing), but for a DIY with limited wiring skills the Visonic is hard to beat.
it also emails you every time it is armed or disarmed, if there is a power outage, and if someone tampers with one of the motion detectors or sirens (like if someone gets a ladder and rips the outdoor siren off the wall) Also has battery backup so it can keep running for about 24 hours with no power at all.