So I took the plunge and purchased DOOM Ultimate from ID Software and was able to get a “DOOM.WAD” file, threw it in the Doom Roms folder and I was good to go! Thanks again for the help petrockblog!
I was just looking for a .wad file that would allow me to test out the game before I made the decision to buy it, but I just gave in and purchased it to make my life easier. Everything works great, actually I can’t believe how fast it is and it works with gamepad controls too!
My only minor complaints are that I’d have to reduce my display size to be able to see the top text properly on my composite LCD and the buttons are mapped kinda weird on the gamepad but I can fix that in retroarch.cfg for DOOM, just too lazy.