Howdy @1rocky, first off they are the larger side of the Jayco, and I presume you must have a 4 door given the 2000kg quoted tow capacity. First off the tow bar is rated at max 2300 (from memory that a diesel 4 door auto), the vehicle is rated at 2000, so 2000 it is
As for towing it, mine was a manual sport so had the much taller gearing and a clutch... and I upped to 33's. It was a pig off the line and shocking at hill starts. With the Rubi's 4.1 gearing and the auto you should have no probs at all. However, I would recommend the extra auto cooling for long uphill halls or on the beach.
My only comment is to check clearly the tow ball weight!! I was looking at the littlest one, the Swift from memory, and ball weight was only 80kg. Also looked at the Hawk, about 110kg from memory but the missus decided on the Dove and I never looked at it just assuming it was in the middle around the 100kg mark - it is quoted at 128-155kg but weighed in at 190kg... Over weight technically for the 2 door I had (160kg max) but gave me no probs anyway.
2 in lift is no probs, I had a 2.5in and 33's on mine and it drove and towed better than stock.
As for which one? 4 adults and a bub I would be going for the biggest one you can tow!!
Also don't go for the Jayco standard awnings, poor quality, the next one up is the best option though off the top of my head I can't remember the name but I can look it up for you if you if you are interested (Kakadu maybe??) I can thoroughly recommend the Kitchen and bed end awnings and of course the full annex is a must though we only use the walls rarely.