Gotcha. Any cheap dust cover should work, and should have the ledge.
As for the safety selector, it's a bit pricey, but I recommend the Krebs Enhanced Safety Selector
It has a finger ledge that you can reach without removing your hand from the grip, and also has a cut out bolt hold open.
Might also want to replace the trigger with a(nother) Tapco G2 set, which should replace all the parts that could be causing this.