on paper you have worked out to 900kg but in practice it will be over,
my van with a 1000kg payload with just a leisure battery,600l full tank/frame, hose reel, heater and a gas bottle, no ladders with half a tank of diesel was 10 kg off the gvw on a weigh bridge with me in it
a connect is only 900kg payload, and you want to add more water, another passenger and another hose reel,
I knew someone who had a 500l tank in a connect t230 and with the tank full it was over the gvw on a weigh bridge.
as someone else has recently said he had a vivaro 2700 on a weigh bridge with a 650l tank and 2 men inside and it was 200kg overweight,