Um, I've tried bezels on my 27" and it ain't big enough to make at least vertical games the right size. A bit small. I don't think the bezel idea is a great idea, given displays aren't really made with such in mind. There's always going to be some compromise. Besides, if running native, you can't use artwork.
wb, this picture is on my candy and slightly smaller than the display field, as the geometry is set for games of 336x240. The hardware scanlines are apparently larger than on a 19" monitor. (Make sure to click inside the picture itself to magnify.)