Looks good, only criticism would be I would get rid of the wood, with all that water it will just go mouldy,
The tanks I am not keen on because the baffling is pretty poor and the weight distribution on the vehicle because is it a upright tank the handling of the van will suffer.
Its good that you have somewhere to put your poles but there is no need to keep DI units in the van, finally I would have mounted the controller where it can be reached from the back door