Help with low level deck please!

Hi. We are wanting to build a low level deck and being novices, I have been scouring this site for some tips. The deck is going to be quite big (about 75sqm in total) and its off the house, forming the "patio" and continues around the pool (salt water). I have about 20cm between ground and top of coping. I have a few questions:

1) because of the salt water, should be use something like "protect-a-deck" which some of the timber merchants are trying to sell me?
2) I like the look of belau. A friend has it and the colour variations are nice. Is this OK to use?
3) I take it that the screws are really important, especially around a salt pool. Can someone recommend the best screws which dont require pre-drilling please?
4) timber merchant is recommending fishtail stirrups. My builder friend is thinking of reinforced concrete trenches as bearers. Some say just lay the bearers (T4) straight into the ground. I want the easiest method. We have hard red clay to work with.
5) can someone recommend where best place is to buy timber. we live in the western suburbs of Brisbane. I have only been to AAA Timber in Sumner Park and am waiting for a quote from them.

I would appreciate any help.:)


More...