Nopes, 8th was never legal with Ravnica, I believe. Ravnica was legal with 9th (release Jun 05 - before Rav), and I'm not sure if it was legal with 10th (I believe for a short period, at the end of Rav-TSP t2?)... Alara was the block after Lorwyn, so that would be 10th, M10, and M11, I believe, so the rest of your period would be correct, with the exception of 8th?
In any case, though, given that the choice of Rav+Alara blocks appear completely arbitrary, wouldn't it be better to just play Choose Your Own Standard (any 2 blocks + any (4th and beyond, I believe?) Core Set)? Gives more flexibility, in any case - just that we would have to formulate a banned list of our own?