I've just opened an open air mini mall on the mainland in Slitheen at 22, 10, 68.
There are 12 shops available offering 50prims per a shop for 250L per week. The minimum rental time is 1 week, the maximum is 15 weeks (but nothings stopping you from renewing and extending it). If you rent for more then 10 weeks at once, there is a 5% discount.
The land is rated Mature so you can sell anything you want!
I have also applied for an SL Exchange ATM to be put on the lot. so it might help bring in customers.