i have did some 960 x 540 fonts in the old forum, i dont know if someone had saved, i have those in my home but im not in home right now i have the template for this size and i send to you when i reach my computer
BTW you can simply double the size of original fonts and they will work fine. Open in photoshop/ggale/gimp and increase size by 200%, tick maintain aspect ratio.
Actually the size of font image doesn't matter. OpenBoR will get 16x16 letters from it. So if rafhot's suggested font is not good for you, you can rescale it to any desired size.