Hello Rock4350.
Yard Power District Wiring - Now And For The Future
Since you have double-insulated tracks at both ends of your yard, you can run power into your yard off the same command station/booster. OR you can set up a separate power district. AND, if you decide to power your yard from the same command station/booster, you can wire the yard so that, if, in the future, you want to set up the yard as a separate power district, it's a simple matter of cutting in a power manager device (like the Digitrax PM42). The choice is yours.
To wire the yard for the future (or the present if you want a separate power district), you would run a 2-wire buss of 14 or 16AWG wire (the recommended way to do things) the length of your yard. You would solder in track feeds (about 2 or 3 per track as your yard is about 8' long) to this "yard buss". You would then solder the two wires at one end into your main track power buss.
Use some trailer hook-up wire that you can get from an automotive supply store because it comes in different colours, comes in different wire sizes (12, 14, 16, 18 AWG) and makes wiring very easy. You can get your track feeder wires from you LHS or from an electronics store - suggest 20 or 22 AWG. You simply follow the colour codes, say, red wires for the back rails and white wires for the front wires. From there it's a simple matter of connecting red-to-red and white-to-white. Here's some tips on how to do it.
Installing the Track Power Buss - Page 1
Frogs And Turnouts
There's a lot of discussion on other websites about the modifications you HAVE to make in order for the turnout to be "DCC compliant". If you've got to hack a turnout apart to make it "DCC compliant", I suggest you use another brand of turnout.
To be "DCC compliant", the frog of the turnout must be "insulated". That means that power from the point rails cannot conduct electricity through the frog. Some turnouts, such as the Peco Insulfrog, the Atlas Streamline, and the "newer" Shinohara and Walthers turnouts are already "DCC compliant". Other turnouts such as most handlaid ones require some MINOR modifications. The mod is usually to cut the two rails beyond the frog. (By the way, it's not necessary to put insulated railjoiners at all 3 ends of the turnout.)
So, you now say the frog is not powered! How will my locomotives get power!? If your locomotives have pickups from both trucks - whether on a diesel or from the tender - there's no problem. If your locos have pickups from one truck, you might have a problem - maybe.
What about "power routing? IMHO, it's over-rated. As long as you have the frog insulated and track feeds somewhere near the point end and two somewhere on the other end of the two diverging tracks, you should be okay. To get a better idea of what I'm talking about click on this link.
Installing the Track Power Buss - Page 2
You will have more concern about 6-axle diesels shorting out on the frog than any problems you might encounter because the frog isn't "power-routed". The short on 6-axle diesels occurs because the back axle touches the edge of the diverging rail on the pointed part of the frog - usually on short or medium length turnouts (usually anything shorter than a #8 ). It's a simple matter of filing/grinding the top of the pointed part of the frog back about ¼" and rebuilding the frog back up with some epoxy. Hey, you'll be following prototype practice where the railways weld the frog to build it up because of the wear and tear on the pointed end of the frog!
Hope this helps.