When using a ground mash its a good idea to go with a much higher percentage. That type of mash will mold more easily unless you can remove the oxygen. Chunks of peppers you can simply keep under a bring line. Mold aint gunna grow worth a damn on salt water. When you process the fermented pieces you dont have to use all your brine either. My cayenne ferment is on its 4th day in my E-Jen fermenter and it already has a sour smell. I used around 2% salt by pepper weight and made a brine to cover them. Caldwell and similar starter cultures make a huge difference in how fast they begin to sour. They are just stupid expensive. A bottle of probiotic juice is way cheaper and will do the same thing.
They do make a fermenter with a pump to remove the air inside the Mason. How well it actually works i dont know. Kits are around $25-$30 and you need some large mouth jars too.
I have these lids and pump. The pump pulls a very good vacuum. Once CO2 starts the vacuum is replaced with pressure. We just made some kraut not long ago and the odor in the kitchen was,......well like fermenting kraut! I have used air locks in the past and much prefer this system.