REAS IS available on the 3 day land/ 4 day sea. That is what I had back in April/May.
Disney has been known to 'try' to prevent people from purchasing the REAS for that land/sea combo. They try to push the $599 romantic package. So you may have to fight to get it. But the 03 & 04 brochures clearly state that the REAS is available for the 3 day land 4 day sea.
I believe Disney will close that option for 05.
However, right now the REAS is a deal, especially with the increase in fees out of the Spa. They raised the couples massage from $189 to $242.
Personally, I don't believe the Romantic package is a good deal on the 3 day land, because it would really crowd your schedule. Its only worth it if you've been to the parks before, and you are actually traveling as a couple.
And to be truthful, I was being a little 'snippy', actually snippy/funny. I think the search tool on this board is excellent, and people would get better answers if they used it more.