What better place Arduino model for my tasks

Hi All!

Tell me please, what better place Arduino model for the following tasks:

  1. Interaction with the computer on COM port. The computer will send commands Arduino, and Arduino will respond to them. The command system will be implemented in the program on the computer and in the programme for the Arduino
  2. Arduino should be able to manage power supply GPRS modem Siemens MC35i. Arduino must know how to enable and disable the modem Power supply. Power supply of modem 12 volts.

Where to buy Arduino with delivery in Russia?

Perhaps in the future will need the following devices to connect to Arduino:

  • Sirena
  • Motion sensor that is triggered when moving Arduino

Are there such devices?

Thank you.

Anybody, please answer my questions.

The Arduino Playground holds the answer to a few of your questions,

http://www.arduino.cc/en/Main/Buy
^^ Where to buy an Arduino, sorted by continent, there are no stores specifically for Russia, but some of the european ones should work.

http://www.arduino.cc/playground/Main/InterfacingWithSoftware
^^ Guides on how to interface arduino with many programming languages/softwares.

I’m not sure about the Seimens modem question though.