Gooseneck questions

[13MWZ]

I have never towed with a gooseneck, only bumper-pull, so I have a few questions I'd like to ask before I install my first gooseneck.

First off, how are the trailer wires ran? Do I need to put a connector in my bed like 5ers use or are the trailer wires able to reach the connector on my bumper? Will it differ from one trailer to the next or is there some sort of standard? If I need one in the bed do they make them that plug into the stock harness or will I need to splice a new connector into my wiring harness?

Second is about the saftey chains. On my bumper pull trailer I always cross my chains, is that a good or bad idea to do with a gooseneck?

Third consourns the brake controler. My truck didnt come with one but came with a plug to connect into the harness and splice into the controler. I dont currently have a controler due to my loads being so light I never felt it necessary, but with the gooseneck I'll need one. What do I need to look for in a brake controler? What are some good ones to take into consideration......or would a $60 one from the auto store work just the same as a $120 one from the trailer store? Just curiouse about what the differances are.

Also, I'm planing on getting the hitch with the flip over ball from the dealer for $500 and install it myself. Has anybody used this one? How was the install? How much (if any) drilling was required? I believe they advertise no drilling required but I've heard that before and still needed to drill.

Thanks for yall's time, advise, and help.