Yesterday I had some time to spare so I decided to install the electronics, instead of installing the rudder servo. That added "some" wires to the boat. I decided that the best way was to put everything in place by using tape and Velcro. That will keep everything in place and be easily removable.
By using Velcro to fix the battery it can easily be moved for balancing reasons. I cut the red wires in three of the ESCs so only one will feed receiver. All electronics seems to work. Only thing is that the ESCs are different, meaning they don't start at the same threshold. Let's hope that won't be a problem.
Here are some pictures of the installation: