Eagle Pass in Oviedo see Rudy
Lukas for certain plants / mostly retails prices
South Seminole Nursery in Casselberry see Jim
Appenberry's in Orlando
Blodgett's in Orlando
Biosphere for natives etc
Lazy Sago in Geneva
There are many more, it just depends on what type of plant material your looking for.
Unfortunately, in my experience is that there is no single source vendor for everything. But then again that just depends on how large (or small) your plant pallet is and how demanding you are on plant quality for the job.
Additionally, Plants are living things and are not "stamped out" so quality can change from week to week/day to day even at the same nursery.