Bitmap fonts. Same font, different sizes


I would like to know if you know any site that sells pixel fonts with different pixel sizes. Fonts for flash do that, but only with different fonts.
I mean, font a with 9px, and font b with 11px

What I want is the same font in a variety of sizes. Typotheque did this with fedra bitmap font. This font was available in the 9, 11, 12 px size. But i can’t find any other font like this one…

Thanks for your help.