Flash w/ HTML

So we're working on building an almost completely flash site for a client, and they refuse to knock the level of flash down to a decent level. Thus, we want to build a mirrored HTML site for SEO purposes. My question is, what has everyone used/done/seen success with in regards to redirecting search bots and human users to the HTML and flash sites respectively.

I'm assuming a robot txt file will direct the user accordingly. Does anyone have suggestions otherwise or suggestions for simple programs that will create the necessary files for us.

Thanks in advance

 

Make a intro page where the user can choose which they want.

 

I'm not so much worried about the user as I am the search engine bots. I want to make sure that my HTML pages are the only ones visible to the bots.