I'm working on getting the "subject-line" up and running with an arduino (all arduino hardware and software for prototyping with a port to C if possible even though it is usually done in reverse order).
Another important aspect is optimal power management like the waspmote in deep sleep mode waiting for a trigger by the user. It's under 1 microAMP.
What do I need to get in order to get this up and running? Do I need three arduino boards (1 for each gsm SIM) and the third to talk to both of them.
How would I set this up so it can send calls, sms, send gps coordinates, sync data over wifi, , display simple text on an LCD. I have the following so far. Adafruit Fingerprint sensor.
I have a sparkfun red board inventors kit and linkit one but I want one platform to just work with everything and everyone else seems to be playing games.
My hope is Arduino is different.
What do I need to get in order to get this up and running?
A miracle
That sleep current not feasible and that sounds to me way too much for how much memory you have.
What do I need to get in order to get this up and running?
A very good low power specialist like me 
you have to forget your red board and start building standalone Arduino on a breadboard to start with then you will actually need a very good measurement utility to measure the current that your system on breadboard is eating up (low power current measurement that too accurate ain't cheap and simple as it may sound)
nevertheless you can forget about current measurement to start with and start writing code to drive the connected sensors/chips etc and when all the basic communication with sensors/chips are working and they are spitting what they want then from their you can begin doing a bit of current measurement and use low power utility on ATmega328p to actually save power.