I need advice on which cover up to buy?

I've been through so much foundation, a lot. I have very,very oily skin, acne prone, and visible pores, and a lot of dark acne scarring. I want full coverage and foundation seems to be the only one that gives me that, but after, when my oil starts producing, it gets really cakey, tick, and heavy. Powder is too light and doesn't cover much. Now I'm thinking about buying a very good concealer to conceal my acne scars and pimple and use a heavy powder on top. Which one do you think is the best? I have really bad acne scars. Foundation alone, powder, or concealer and light powder. Can you give cons and pros for each one too? Thank you!