Cdawg, first welcome to the Afourian Forum.
David,it is basically just wiring and there ar wiring kits that do make it much easier to do. I am in the process myself at this time. I am using a bundled "romex type" wire that has 2 #10, 2 #12 and 4 #14 fo rthe gages. It is a common product available in most marine and hot-rod shops, you buy it by the foot and go to work. It really isn't too difficult if you go one step at a time and take the time to route the leads neatly. Many on this site have re-done the Catalina's with this very issue. My Ericson has a similar set up and since it is now 43 years old I'm just re-doing it before I have any issues with it.
Dave Neptune