These are not currently on the Virtue site, but they are still on the GR Research site, so I don't know their status as a vetted supply...
But, if anyone has been contemplating one of these kits, and worrying how much DIY skill is involved, I know the answer: next to none. I have a little so figured I could manage it, but I think even with next to none you can get it up and running in no time.
Here are the batteries and premade cables and connectors, out of the box:

My plan was to stow the batteries on their side in an ex-Audio Alchemy CD transport box. (In other words the nice black box isn't included; if you want a box, you have to come up with it.) The directions are at the side of the picture, and disconcertingly spare: a copy of a picture of the batteries hooked up, with red and black connectors colored in with a Sharpie.

However the longer cables that go to the red and black connectors are, helpfully, red and black. The only question I had was the short connector-- which side was "red," which "black"? Did it matter? The shorter cable's connectors have a flat side, and a semicircular side, and depending on which is considered "up" reverses the connection. I decided the semicircular side must be "up." I hooked it up that way, and the multimeter gave the appropriate readout.
After connecting the batteries, there is one slotted connector to join that hooks the cable up to the charger, and another that hooks the cable to the cable that runs to the Virtue amp. Here is a close-up of the connections.

I wanted to use the IEC connector already in the Audio Alchemy box, so don't be distracted by the little PCB board at the bottom right; you won't face one. You can just plug your power cord straight into your charger.
So, really trivial in terms of the skills involved. I put a nice wood face on the box and it sits under my computer monitor now. Making the wood face was quick work, but even that took far longer than the ten minutes it took to hook up the battery supply. If you haven't pulled the trigger on one of these supplies because you think it would be difficult to make, think again, it isn't. And while I could perhaps have shaved a couple twenties off to source all these supplies myself, I would have had an awful lot of unfamiliar information to digest in order to do it; it would have taken me hours and hours to order the parts for an appropriate supply, whereas the time I invested in ordering the kit online, then assembling it was thirty minutes tops. So well worth it to me.
The next time I want to use a battery supply I may well do it myself-- now that I understand what is involved-- but for this time the kit was the perfect answer.
