To the OP, what exactly are you going for? Are you trying to clone a commercial example? Do you want the typical spicy peppery character that is typical for the style, or is it more saison in grain bill but less so in fermentation profile?
Just a couple thoughts, if you use pedio, you have to use brett. Pedio will generate diacetyl which brett will clean up. Without brett, you'll end up with a sour beer with buttered popcorn character...aka gross.
If you want to turn it around fairly quickly, I'd go with lactobacillus for souring. Souring with with lactobacillus gives more complexity than you'll get from acid malt alone.
I haven't had much luck souring pre-boil but lots of people swear by kettle souring or sour mashing, so check out those procedures. As mentioned, you can kill off the bacteria via the boil, so it eliminates sanitation concerns and locks in the sourness level. And you don't have to worry about IBUs or hop oils causing problems for the bacteria.
If you sour post-boil, pitch the lacto and let it go for 2-6 days before pitching a sach and/or brett strain. Don't aerate...in fact, purge your fermenter with CO2 if possible. Giving the lacto a headstart allows it to lower the pH without having to compete with yeast. IME, room temp works fine for this process. I've done this with Berliners, a Sour Saison I made, a Flanders Red and so on. In all cases I had no problem getting the pH down in the neighborhood of 3.0, which results in a pretty tart beer. Oh and keep the IBUs low...or non-existent. I use aged hops in most of my sours, so the IBUs are pretty close to zero.