Timed Arduino, Solar Panel, Battery & 12V Pump HELP

Hi all,

I'm a struggling to do a project in less than 1 week for a charity and wondering if the www can help. I'm a complete electronics/Arduino beginner so please break any suggestions down, thanks!

The challenge:
I need a little water pump to run for 3 seconds with a 10 minute pause completely off the grid 24/7 from a battery. I need the battery to be charged using a solar panel and hold enough storage to run 2 days without sunlight. An Arduino is also needed to change the duration and interval of the pump.

What I know:

The pump requires ~12v @ ~270mA (5W)
and 64.8mAH (for 2 days of operation)
(pump runs for 18s per hour = 0.05h per hour
0.05h x 270mA = 1.35mAH
1.35 x 48hrs = 64.8mAH)

I also need to be able to take the battery on a flight so please recommend a suitable battery for the system (I was thinking maybe the Li-ion 18650? http://www.ebay.co.uk/itm/311727421481?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT).

Pump: http://www.ebay.co.uk/itm/222223864810?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT

What is the simplest way to wire & code everything up? (Please also recommend any required components)
Any help is much appreciated!

If by flight you mean a plane and not a set of stairs then you are out of luck anyway.
For the rest I would try to use simple timer relays instead of an Arduino.
Cheaper too...