last summer we flew into Sanford on Pan Am. I searched all around and most of the limo services seemed about the same. We ended up taking Tiffany and were very happy with them. With the tip it cost about $200 roundtrip to the Dolphin, even though there was only 2 of us, but the Pan Am rate was so cheap we still saved money. (Although if I did it again, I'd probably just rent a car) It was definitely much farther than the Orlando airport, and nowhere near a grocery store, so he dropped us off at a gas station as our grocery stop - not at all helpful.
There is no Mears shuttle from Sanford. Sanford airport was extremely easy and quick to get around. (i.e. small)