Hi Marcy,
The effect you see on that web site has been done using Flash.
If its a fade transition effect you are after you can achieve this using jQuery code. That way you wont need to buy Flash. The code for the effect is open source.
Take a look at
http://www.malsup.com/jquery/cycle/The effect you want is the 'fade' effect.
Let me know if you need any further help using jQuery plug-in.
Gary