Yep, it's possible, just set the aspect ratio in mame.ini to 16:9 (that should be what your tv is) and the games will be pillarboxed so you have the correct aspect ratio.
As for mala, the way I did this was by making a layout at the resolution of my display, but I only use the area of the screen that's in the 4:3 "box" if that makes sense. I just filled in the rest with black which gives you a pillarboxed image.