Hi Bob, I'll give you my experience with a Picasso C3 1598 cc petrol (2009) power 88KW, Max braked weight 1100kg. I believe the nose weight of the 'van is about 50kg, or less as the 'van is the rear kitchen layout and is quite light on the tow ball and is not heavily laden in use !
Previously I used a 2ltr Diesel Berlingo Multispace, to tow our Eriba Puck L (750kg).
The Picasso is a dream to tow with as far as handling and comfort are concerned, behaves perfectly :) However there is a marked difference in performance over the old 2 ltr. diesel Berlingo ! Yes i it drives quite fast enough, but you need to use the gears at the slightest hint of a gradient, and use the revs to maintain quick get away progress - it does it, but you know it's working !
I don't have experience of the 1.2 engine,- which may have superseded the 1.6 but it may be that the further lack of torque will make itself known when towing. I really think it's a shame that these modern engines are under so much stress to produce 'adequate' power for normal driving, but may find itself lacking under other than normal use.
To sum up, you can expect a good comfortable towing experience with the C3 Picasso chassis, but may find the smaller engine a little 'hard-work' It really is down to what you need, and how often the car will be used for towing !
You may, of course, consider the Diesel version ?
Just my opinions
Hope it's been of some help.