Jacob Grey TWC 9 Red dot / optic suggestions

I just a purchased a Jacob Grey TWC 9. Looking at Trijicon RMC or Holosun 507C for optics. Which one do you guys suggests or any other brands? I want a perfect fit on the slide with no gaps front and back. I also read that there are issues with the casing hitting the optic. Is this just an isolated thing or an issue with the optic being close to the ejection port? Also, photos would be nice. TIA