How to build an arduino GSM GPS tracker

Hi
For a high altitude balloon I want to add a GSM Tracker as a backup to my other tracker. I thought about buying a commercial one, but then remembered that I might as well build my own.

So I found this online.

Would that work? Does it support the standard GPS library?

How much current would it draw if I only sent an SMS every 10 minutes or so? I would be running it for maximum 6 hours on battery.

Anyone?

How much current would it draw if I only sent an SMS every 10 minutes or so?

Build the system and measure the current.