
Here are a few things off the top of my head for incorporating games that would be found in a candy cab.
Most of the vertical Taito Type X games don't like running on a horizontal monitor.
Howard Costa made some wrappers.
http://dragonking.arcadecontrols.com/ (under misc downloads)
People have had varying success depending on the game and their hardware.
Some of them refused to run at the same time as my front-end, so I had to use an autohotkey script that closed my front-end, launched the game, then relaunched my front-end on exit. It works, but I'm still working out the splash images to hide everything during the transitions.
I probably spent my entire day off work on it, but I have every single one of them working on my new cab.

For NAOMI games, I ended up using Makaron for Dead or Alive Millenium, Marvel Vs Capcom 2, & most of the shmups.
It may have been my processor, but they just ran better using Makaron than Demul. If it's NAOMI 1 and it doesn't work right in Demul, try it on Makaron. I'm using 12.7, but the download of it is missing a lot of documentation, so you may want to grab 12.5 also. It's a PITA to set up if you haven't followed dknute's blog through it's development. His releases weren't really made with public consumption in mind. You get whatever state it was in when he was working on it and felt like releasing it. I'm grateful he shared it. The roms are probably a PITA to find as originally he used .dat files and then switched to MAME roms
for most games. I guess look at the date of release and see which MAME version was current at that time. My collection is a messed up assortment of both that I acquired at the time the emulator was released, but they all work.
There are some autohotkey scripts in the software forum I wrote for launching vertical games on a horizontal monitor in Makaron. Search for "autohotkey fun". They need some tweaking. They work fine on the PC I wrote them on, but on my arcade setup, they probably fail to black out the window frame 20% of the time (the desktop is still blacked out). I'm sure with some tweaking they'd be more consistent.
The other PITA thing with Makaron is that the games will fail to launch unless the screen orientation and number of players is set up correctly in the service menu. Makaron doesn't save that individually for each game. If you change it in one game, it will be wrong for another game.
I ended up with four Makaron folders. 1Pvert, 2Pvert, 1PHor, 2PHor.
It's a hassle, but worth it IMO if the games don't run as well as you'd like in Demul.
Wow, I rambled a lot for no question being asked.

I'll shut up now.
Let me know if you hit any roadblocks.