G'day Jackson,

The Ridgeback HighRize is generally compatible with most roof racks systems.  We dont actually sell roof racks, so the best bet would be to head to your local roof rack specialist - looks like TJM or Mick Tighe 4x4 are your closest options.  They should be able to let you know the best rack set up for your vehicle and mounting a Rooftop Tent.

G'day Jackson,

For the majority of vehicles, no you can't.  
The standard heavy-duty roof racks have a max load rating of 100kg.  As the 1550 is 110kg, you're already pushing it.
If you happen to have a third roof rack, that will increase your carrying capacity to 150kg generally, but you'll need to pick up an additional RTT clamp kit.
Obviously, if you have the 3rd roof rack, you can look at mounting a solar panel on the HighRize, but bear in mind it has a max 10-12kg load whilst still being able to be opened.
You'll also need to consider your GVM and your vehicles roof load rating to make sure that covers the roof racks, roof top tent, roof top tent racks, and the solar panel.
Hope that helps.

G'day Steven,

The limitations on whether or not this is suitable for your vehicle is based on your roof load rating - not the rating of the roof racks themselves, but the physical roof.  You'll need to determine the physical weight or your roof rack/platform system, and add that to the total weight of the roof top tent.
If that combined comes under your vehicle's roof load rating, you should be good to go.

G'day again Craig,

Not suitable on the cab roof I'm sorry, both from a size & weight perspective.
The latest rangers only have a cab roof load rating of 85kg when moving, so you could possibly get away with a roof top tent if you went with a much lighter option.  I've never actually seen a rooftop tent on a dual cab roof without significant hang over the tray which is supported by some kind of framework or Ute/Truck box.

Sounds like a Camper Trailer will be the way to go if you're not keen on the tub racks.

G'day Craig,

Generally roof top tents can only fit to dual cabs utes with a tub rack.
You may need to make some inquiries with your dealer on whether or not there's an option to fit a tub rack to your vehicle, something like this.  Often the newer models have a roller cover which means the generic tub rack options are not suitable.