Nothing wrong with a centerboarder at 27 ft, I have one at 44 ft.
But as others say to much work needed. Even if free it might be too much.
In fact if this one http://orlando.craigslist.org/boa/4109964575.html
it is something to avoid as he has done a DIY delamination blister repair which might be failing already. An expert is needed!
There are a LOT of bargains around in Florida.
Something like this 24ft bristol sailboat diesel