Split charge kit.. and more

[rollercoaster]

Please, is there a good kit or a link to someones setup that explains how to do it?
I would like to fit a leisure battery in my DOKA with the possibility of not only charging while driving,
but also a mains hookup charging sometimes, as well as later additions of solar panels possibly.
I will need to run some 12v power out to a cara van as well so some outputs would be great.
Not having much fun looking for what I want and unsure how bits and pieces would integrate.
There is a battery in the cara van but it seems sensible to keep the main auxiliary power in the truck.
Would like to be able to charge up fast so thinking heavy duty..
Also when linking to cara van from truck, cara van battery could well be flat, so big current surge.
Thanks for any tips.