Looking for Font Preview script

I’m interested in making a font site for the fonts I create myself, and I need a script that is similar to the one found on many font websites that allow people to type whatever they want into a text field and it will generate a preview of their text with the selected font. Ultimately it will need to have the ability to let someone enter text, change size, change color.

I’m sure I could edit the code myself to show hard previews of what the font looks like in columns, full width, header examples, etc. but definitely need help with the preview area.

http://www.fontsquirrel.com/fonts/source-sans-pro (click test drive tab)
http://www.myfonts.com/fonts/hvdfonts/brandon-grotesque/webfont_preview.html (click webfont tab)

I think you get the idea?