Composite to HDMI converter that preserves 4:3 ratio?

Looking at getting a new TV and I've noticed many newer models only have HDMI input and seem to have dropped composite/s-video inputs.

I've found a number of Composite and S-Video to HDMI converters on Amazon, but the reviews on all of them say they stretch the picture to 16:9 instead of preserving 4:3 aspect ratio.

Are there any recommended converters that preserve 4:3 (put black pillars on the side) instead of stretching the video?