Hi,
We tow a Lunar Lexon 640 with a 2.0tdci S-max although it has a mtplm of 1600 it's miro is similar to yours at 1266kg. It's performance towing is good for a 2.0 maintaining 60 mph up most of the hills you find on a motorway, though we almost never use 6th gear. This is our 1st car with cruise control and we use it all the time solo and towing, we would never go back to not having it. The parking sensors are a pain in the a++e, constantly beeping away when you are anywhere near another obect, if they only worked within 6" or you could just switch them on when you want.
The torque of the 1.8 is similar to our old VW Sharan which coped but was down into 4th gear on every hill.
Can you pay the difference to get the 2.0 titanium?
As a towcar the grip on wet grass is better than expected, about as good as you'll get from front wheel drive and stability is excellent, overtaking artic's perhaps faster than is legal there is barely any feel of the outfit being pushed around.
It's the first car Iv'e had for a long time to actually put a smile on my face, it goes round corners like no 7 seater has a right to!.