I also prefer lower sulfate levels, basically, I just add enough gypsum to get my Calcium levels to ~60 ppm, then I add sea salt to give me a decent Sulfate/Chloride balance (I like 1.5/1 or 2/1). The resulting sodium levels are anywhere from 20-40, depending on what exact profile I shoot for. I had been using acid malt to adjust pH, but my newest batch seems more acidic than previous batches, so I am switching to regular acid.
Through some experimentation, I am beginning to believe that increased sodium levels permit higher sulfate levels to taste palatable and not come across as harsh/astringent/bitter. I have had very soft water in most of the places where I've brewed (Portland, OR and East Bay Area, CA) and found that I found my beers unpleasantly harsh when I brewed with more than 150 ppm sulfate. However, I remembered that when I had just used "burton salts" with RO or DI water before, I hadn't noticed the same problem. I also tasted plenty of great homebrew from people using Tasty's pale ale profile...
Anyway, I finally considered that my super-low sodium level might be the culprit, and started testing out higher sodium levels (20-50 ppm) by adding sea salt. Sure enough, higher sulfate levels are a lot more tolerable with sodium levels over 20 ppm. I've stopped using calcium chloride when I adjust minerals for hoppy pale beer. Now I adjust chlorides by adding sea salt, then increase the sulfate and calcium levels to get me where I need to be with gypsum. The balance has worked well for me, flavor-wise.