I have a few F40T12's that I'd like to showcase.

I bought a Lithonia Lighting F40T12x2 strip from HD, but the ballast is a crappy Keystone ballast, really more like a LOA-in-a-ballast-style-enclosure. This type of ballast, I learned, are not good for the lamps. Underdrives F40's and has high crest factor.

So, I decided to go another way. I have a way to get custom woodworking done, and I would like to build a vertical, wood column that holds 8 F40's in a square pattern layout (2-2-2-2) and I can select which lamps I want to operate. I would like to find 4 good ballasts to run these. My preference would have been NOS rapid-start ballasts, BUT, I vaguely remember that rapid-start ballasts require a grounded fixture and the lamps to be within an inch or less of that grounded fixture to start properly. And NOS 120v ballasts are kind of hard to find.

What kind of ballasts would you guys use? I was considering something like a true electronic ballast that is rated to drive F40s at full power, as these still seem easily found. I do understand that they are WAY less reliable than magnetics, but if they are safe for my lamps and run full power I would still be inclined to use them.

Honestly I'd recommend preheat, since i hear they are good on lamps, but since I am more in the HID field of things I'm sure others will maybe disagree... rapidstart would be a no go, and electronic I personally would not choose, since they don't tend to last as long and a lot of times when they get close to dying they make a whistling noise that really is harsh on the ears...

Yeah I like the idea of preheat! Didn't even think of that yet.

You could router the back side of the wood and run a copper wire down it, or even the front side if you like the look and color of copper and clean the copper with vinegar and salt to make it shine, router a line or pattern and cover it over with Circa 1850 finish it's self leveling, sandable and easy to polish, you can then use this as your ground requirements, or you could cover it over with a veneer overlay,  And I would go with a programmed start ballast if you want them to last a long time..   

A Fulham workhorse ballast might be good. They are instant start and the ballast itself needs grounding. They're also really cheap and efficient. I don't know how they are for bulb life, being instant start I imagine if its turned off and on a bunch it would wear the lamps more. A wh8 will run 5 f40t12. Fulham's website has a page with information on what lamps it will officially drive and how to wire them up.

https://www.fulham.com/contact-us/wiring-diagrams/

You could router the back side of the wood and run a copper wire down it, or even the front side if you like the look and color of copper and clean the copper with vinegar and salt to make it shine, router a line or pattern and cover it over with Circa 1850 finish it's self leveling, sandable and easy to polish, you can then use this as your ground requirements, or you could cover it over with a veneer overlay,  And I would go with a programmed start ballast if you want them to last a long time..   

I'm not finding any T12 programmed start ballasts online, do you know of any to recommend?

Not offhand. You might try and look to see if other companies including Fulham make some more universal program start ballasts or ones that have similar characteristics to T12. Do be afraid to think outside the box. I've used workhorse ballasts to run all kinds of HID lamps even though it is not rated to do so.