having looked into booking privatly to go to estatit i found on my web travels the site for the miami apartment i will go and see if i can find the link for you.
not sure of any other coach companys right now , do ferris and seista do seat only you could get a seat to there nearest resort and then transport to estartit on your own, just an idea,
another one is, it is possible to actually get a train from london to very near the spainish border, not sure about any nearer tho so you would probably need to get a bus from there.