Dr. Daniel Amen just published a new, updated version of his ADHD bible, Healing ADD. In it, he outlines 7 types of ADHD (so it goes way beyond in hyperactive, inattentive, combined classifications) and specific treatment protocols for each type. Each protocol addresses both medication and natural supplements, dietary changes, and other non-medicinal coping strategies. Assuming that you don't live near one of the Amen centers and have thousands of dollars lying around to spend on treatments that aren't covered by insurance, you can still use the info from the book to guide your children's treatment. The website amenclinics.com has a questionnaire that can help assess which of the 7 types of ADHD your child's pattern fits into and then from there, you can read up (in the book) on what treatment protocols he has found to be most effective for patients with a similar profile.
I have a whole library of ADHD books (my oldest was diagnosed 8 years ago, my husband has it and my 10 year old looks like he possibly has it too) and this is by far the most informative and up to date book on the subject that I've read, to such a degree that my husband ordered the audio version and is listening to it in the car (because he can't focus long enough to read the book). While he is very pro-medication and openly talks about the positive changes he has seen from medication in his patients - including his wife and some of his own children - I like that he is also very open to the idea that medication isn't necessarily the first or best choice for everyone and there are supplements that do help patients manage their symptoms.
As an example of some of the supplement strategies, he recommends that everyone take a good multi-vitamin and mineral supplement (Catalyn by Standard Process is a good one made from whole foods and not synthetic ingredients) and an Omega-3 supplement, with the EPA/DHA ratio dependent on the type of ADHD. Then for classic and inattentive ADHD, he would recommend L-tyrosine, which is an amino acid involved in producing dopamine, but wouldn't recommend L-tyrosine alone for people who have over-focused ADD because it would exacerbate the over-focus symptoms.
In any case...I would recommend this book to anyone, regardless of whether or not you want to continue with medication, because it is so informative. As someone else mentioned, a compounding pharmacy can sometimes work with you to create alternate versions of a medication that your child can take.
Do you know why your doc went straight to Strattera instead of trying a stimulant first? That's a bit of an unusual approach. Just curious.
ETA on the fish oil, Nordic Naturals makes a liquid fish oil that is really tasty. It's strawberry flavored and you just squeeze a dropperful into your child's mouth. They also make a strawberry flavored capsule that is yummy enough for the kids to chew on and then they can either swallow the chewed capsule or spit it out after sucking out the flavored oil. Catalyn is a chewable whole food vitamin (Standard Process only sells through naturopaths and chiropractors, you can't get their products directly).