I never liked the idea of high voltage wires laying on each other. Don't care what the science says...I believe that almost ANY damage to a wire can allow cross firing to take place.
So, I like to keep 'em separated.

There was no off the shelf set up to do this.

I did find a series of generic wire holders that came in 3 sizes, (heights). The tallest was about 4" tall and held 4 wires. There was the med that was around 2-3" tall and the short that was just over 1" off the mount. Imagine an upside down "A" with holes drilled in where ever possible.
They had a single hole at the end for mounting. I used the valve cover bolts to hold 2 and the 3rd off a plenum bolt on the left side. They came in 4 wire, and 2 wire holders in the various height.

These keep the wires up and off of everything and you can arrange the wires anyway you want to use the extra length that comes on several of the wires. You can mount the holders any place you want. They are metal so they can be bent and shaped to fit.
To finish it, I used plastic "clip-on" separators to maintain the spread of the wires between the holders. Those can be found in 2 wire, 3 and 4 wire sizes. The whole mess comes off the dist, to the 1st tall holder, as 2 wires drop off to the rear cyl, then the next holder about middle of the valve cover where the last 2 wires drop off to the front 2 plugs. The driver side took 3 holders while the passenger side only took 2, because of the extra junk on that side the wires route to the plug was different than the driver side which was much cleaner..

Look in the generic 'custom' stuff on the rack at the auto parts store. There will be some holders in a 'pack' that consist of 2 holders per package...the rest is up to your imagination. You may have to hunt for the different sized wire holder...the ones I bought were chrome, but they can be painted.