Radio on vest setup w/jumper for antenna?

Trying to setup my BOB/SHTF vest/setup.

I have a small pack I am going to keep it in most times, but I'd like to be able to carry it on my person as well. It's a small ham radio, Yaesu VX-8DR and Diamond SRH320A.

I have a Maxepdition CP-L radio pouch & it's a really great pouch but it seems bulk any where I try to put it. I've thought about having a speaker-mic routed too, but I want to have access to the radio itself to change channels, get visual etc.

I've seen some setup where the radio is in front & then ran with a jumper cable of some kind to the antenna that was on the back of the vest. Kept the antenna out of the way & was wired nice & neat. Looked like a really efficient setup.

Does anyone know what these jumpers are or where I can find them? Does it take away from signal quality having the antenna on your back?

That Opek seems to fit the bill, but how durable is it & is it waterproof?

Someone on different board posted this & it does look promising.

TCI MAST

Can you hook up any HT radio & any antenna?

Is it completely waterproof?

Any help on picking out what "MAST Cable Version" I need? I have a Yaesu 8X-DR which I believe has as SMA connector?

Looking at that first part of the description it only mentions a handful of radios? Will it work with mine? Does it come with an Antenna like shown in the picture, or just the cable & new mount for your back?