Hi Mc and all,
You need more than a wall plate my friend, you need an outlet box WITH a wall plate. Trot on down to electrical supplies and buy the following;
An outlet box for a duplex outlet with stud mounting flange.
A blank cover plate.
A Romex fitting.
Now along to the radio supply shop for these;
A right angle adapter for PL-259.
A feed through bulkead fitting for same.
You'll need the following tools;
Drill with appropriate size bits.
Coping saw.
Fish tape long enough to snake coax through wall.
And these;
Spackling tape and putty.
Paint to match wall color.
Brush.
While you can figure out what to do with the coax fittings you should consult an electrician on how to snake the cable, mount the box and repair the wall after you rip it apart in various places to draw the coax through or around the fire stops inside the wall.
Are you REALLY sure you want to do this? There's more to it than yanking a cable through a hole in the wall if you want to make a proper job of it conforming to code, not make a horrible mess in the process and run into problems with the fire inspector and insurance.
"Those connectors introduce loss...especially PL259's @ 800MHz."
Macomb, when are you ever going to get over it?
"You'd be better off to skip the fancy connector, and just drill a hole in a blank plate, and run the cable though it."
Yeah, without a feed through bushing the sharp edge will cut into the jacket.
"If you are using RG-8X (the thin stuff), you can terminate it to an F connector and just get a wall plate with the F connector passthrough and that will clean it up."
King, you're right but that "passthrough" is an F bulkhead connector.
"...you can pick up a SO-239 jack and mount it to a wallplate and solder the RG-8 to it..."
Now there's where you went wrong. If you intend to avoid putting a nasty impedance bump in the transmission line you need a hood and properly install it on the back of the connector soldering the braid to it. That's not an easy job and easily messed up which is why I suggested using plugs and a bulkhead (feed through) connector. Another way to do it is put an in line SO-239 on the end of the coax and mount it with a retaining nut, the type supplied with a feed through bulkhead connector. Some VHF ham rigs come with a pigtail and one of those connectors instead of a chassis mount, take a look at one and you'll see what I mean.
Any way you do it you should make electrically sound connections and keep it neat. Treat coax as you would CAT5 cable installed according to code or you run into problems down the road. Life isn't a bowl of cherries, it's a jar of jalepeños. What you do today can bite you on the A tomorrow.