This thread brought back memories. My mom made me take fish oil growing up and it always gave me the fish burps (which she said was naturally and not to worry about). Later in life when I had some money and went into "I need to spend money to buy best of the best supplements hurp-a-derp"-mode (News flash, I wasted a lot of money) I bought some high end certified Alaskan cold press fish-oil. Zero-burps. Now I just go to the local fish mart and buy fish.
The supplement industry as most people know is poorly regulated as-is, and my general advice is to stay away from anything in pill form that can go rancid/spoil and any sort of liquid pills. I've seen way to many crates of pill bottles sitting next to a heater in the back of GNC and other places. If changing temperatures can ruin it, odds are it's probably ruined unless your paying a premium.
As far as 3-6-9 balance I'll leave that to people who know more then myself. I wouldn't put too much thought into specific ratios though. Spend the time and effort finding a local fishery or farmers market and enjoy some good eating + the benefits of the oil. Crappie is a personal favorite of mine here in the Midwest.
Nothing is original. Steal from anywhere that resonates with inspiration or fuels your imagination.... Authenticity is invaluable; originality is non-existent. - Jim Jarmusch