Mineral salt aditions for American Amber mash water

I'm brewing an American Amber and would like to know what water profile I should aim for? I use rainwater so is like RO water. Any help kindly appreciated... Cheers

The neat thing about water chemistry is that you can take any source water and shape it exactly how you want.  Starting with very-low mineral water, you'd want to boost the calcium and magnesium for general yeast health, and then for an amber which (per style guidelines) should lean to malty, you would tilt the chloride:sulfate ratio to favor chloride.  But if you like your ambers hoppy, you might tilt to sulfate. 

How to Brew by Palmer has a great section on water; I think it is section 15-3. 

Thanks for your reply. I'm using Beersmith and wonder how I could use the pre-existing water profiles with my 'mineral free rain water'. In otherwords, what water profile is used for a malty American Amber and equally, what water profile would be used for a hoppy American Amber. I'm not so sure how to determine what ppm of water profile for each of the 5 main minerals so am trying to make use of pre-existing water profiles in BS2 using my water as the starting point. Any ideas??? cheers.

In otherwords, what water profile is used for a malty American Amber and equally.