Quantity   Component name
1 × Waterproof Enclosure Something that fits your batteries and a bit of space for the components. I use Kathmandu Micro Dry Case (http://www.kathmandu.co.nz/dry-case-micro-yellow.html))
1 × Teensy 3.0/3.1 PJRC Teensy 3.0 or 3.1 board (http://www.pjrc.com/store/teensy31.html)
1 × 32.768 kHz Watch Crystal Watch crystal for the Teensy's real time clock
1 × Li-ion/Lipo Battery The bigger the better, and a battery holder if needed. I use two 26650 "5000mAh" Trustfire cells. But any 3.7v rechargeable will do., like the 6000mAh pack from Adafruit.
1 × Waterproof DS18B20 Digital temperature sensor There's plenty of rubbish versions of these - find one from a reputable seller (eg http://www.adafruit.com/products/381)
1 × Sim800L GSM module on breakout board In New Zealand the Sim800L will work on Vodafone and 2Degrees mobile networks. Make sure you get a breakout with the Power Key broken out. I use one from AND Technologies (http://www.aliexpress.com/store/product/Free-shipping-SIM800L-GPRS-Module-with-PCB-Antenna-Automatic-Micro-SIM-Card-SIM800L-breakout-board/605000_32246510568.html)
1 × uflex GSM Antenna This may come free with your GSM module
1 × GSM Sim Card A Sim card with data. One update every 15 minutes will used about 2MB a month, basically nothing,, so a cheap pre pay sim is perfect
1 × 4.7K Resistor
1 × 5.6K Resistor
2 × 1K Resistor
1 × 100R Resistor