You can run games at any resolution you want with vorpX. 4:3/5:4 resolutions are generally best for vorpX, not wide screen resolutions! The default suggestion of 1280×1024 is a compromise between quality and performance. If your PC can run a specific game at 45fps at higher resolutions, you can also set 1600×1200 or 1920×1440 in the options menu of the games.
Reaching 45fps should be your main goal here, that’s the threshold where gameplay starts to feel really fluid. If you can’t reach that even at 1280×1024, try to reduce graphics details.
If you have trouble with Origin, try to disable the ingame overlay in the Origin options. Shouldn’t be necessary, but can’t hurt.