Those DSE sealed lead acid batteries (7.5A/H) work out to like $10 per Amp hour.
Get deep cycle marine batteries, these are around 70A/H and cost $250-$300 (for the better brands).

Solar panels are rated for direct sunlight, with no cloud - unless you are automatically moving the panels via a tracking device, expect them to be running at only about 75% capacity beyond the 2 hours each side of noon.

There are special formulas for working out how to mount the panels, something to do with pointing them due north (in the southern hemisphere) and pitch them at an angle relative to the sites latitude (North/South of equator).

Ideally, have enough battery capacity to run for an entire 7 days with no charge, and supplying a charge (when charging) of 6 times the average power requirement - Remember that a panel putting out 3 times the requirement is only enough to run a site with 8 hours of direct sunlight EVERY day - 6 times is not an overkill, it is a bare minimum. - This will mean that for any good day of sunlight, the gear can be run, and another day of charge can be supplied.


-John