Moog seems to be a good choice since the GM Springs are no longer available like they were. I believe they also have charts for Spring Tension Ratings. I'm not familiar with "qa1" shocks, but if you don't have enough lift in the back with the Springs, there are a few other options to get even a little more height.
By the way, I'm from the old school, lol, and like them raised up some too. Maybe not quite as high as we used to run them, but yet some nice height.
Not only do I like the looks of them raised, but also the cars a have a better chance of not scraping bottom that way. I never understood some of those "low riders" out there.