Operation over a builtup area is covered by CAR262, as mentioned the primary concern is engine type but the aircraft type is also considered with more than the normal 25/40 hours often required especially if the a/c design is the Sunfish Supa Mk1.
Approval is required from CASA or an authorised person. For RAA talk to Steve Bell.
The other option is the Savannah range VG and XL (same base design) for a bit more useful, better crosswind and a bit more speed (even more for the ADV)
Pluses for all are the STOL capability
Downsides are:
Cruise especially with a headwind
Could develop bad habits for other a/c types