So, when I was hunting for 19's that could clear Brembos, it became evident that there's more to Brembo clearance than just offset. The Advans I have coming in a month or two are +50, for instance. My old TC105Ns that I used to have were 18x8.5 and either +45 or +42 and would clear Brembos. When I asked the wheel dealer I was recently working with (RavSpec) about the Work Emotion CR Kiwami, which comes in +42 or can be custom ordered for lower offsets, I was informed they wouldn't clear the calipers. Spoke thickness and design are something to keep in mind, and there's no "number" to know if a particular set of wheels will clear the calipers or not.
I'm not sure Konig has anything in 5x100 that would fit. When I looked, the wheels they have that fit STIs generally didn't have a 5x100 option that works for us. Finding nice 19s for our cars are hard enough, but having wider calipers makes it particularly more difficult.
Some manufacturers will point out caliper clearance. Wedssport will indicate if a wheel clears "big brakes" in the descriptions, but their 19" options are extremely limited. Rays tend to have a column in their wheel specs labeled "BIG CALIPER CLEARANCE" and uses a legend which includes Impreza 4 pots and the STI, and several of their 5x100 wheels share an offset with a 5x114 variant. But... these wheels are significantly more expensive than something from Konig.