NoCatSplash is this possible?

I've picked up a bunch of WRT54G v8 routers...I know, I know, these won't
work with DD-WRT or any other open source firmware that I can tell (at least
the full versions).

I've gotten dd-wrt mini on it, and it works fine, but doesn't come with
NoCatSplash on it.  All I really want is a splash page - no authentication,
no nothing, just free wifi for all that shows we are providing it.

Has anybody found a way to shoehorn this in?  I'd even pay for a service if
I can get this running on these routers.  Can somebody recommend something?

Zachary Burns