Extending F-Keys - is there a F-Key number pad?

I have the wireless apple keyboard which only has twelve f-keys. Does anyone know of a device like a number pad that would add some additional F-keys which I could assign actions to?

Please don't suggest the following - I am aware of these options and they don't resolve a very specific issue/workflow I am trying to enable.

1) just use the fully apple keyboard that have extended F keys
2) use modifier keys for your F keys for addition functions

I have tons of quick keys that I use across the OS, and across apps, and I am trying to find single key presses (without modifiers) that I can press to increase functionality and apple's multipurpose Fkey option makes my goals difficult?

Any suggestions? I love the wireless keyboard, but I just want to be able to add additional keys.

Thanks!

-i