Just sold my mapping garmin gps. The best maps are Shonky! after that T4A but T4a is pretty much dead these days...due to very poor management. Oztopo is free (not as detailed but good enough) and then the openstreetmap phenomenon is really taking off. I couldnt be bothered googling up URL's for links...but im sure you can do that yourself.
But SHONKYMAPS are what you are after I rekon...I have contributed quite a bit of data to mr shonky back when they were being developed so Tassie POI are pretty well covered! I used to host the maps untill they got that popular they took my server down