Schiit Saga which tubes to order?

Marco may be offering the best advice, early Russians have good sonics.
But if it was me, i would inquire which type of Tung-Sol they are offering. It should be an Oval-plate for a price that high. I have one from WWII era in my preamp and paid about $380. Outstanding tube.
A new production TS is inexpensive and isn't in the same league as NOS.

I suspect that some of these "NOS" 6SN7's (and others) may be used "pulls" in old boxes! Nothing wrong with used tubes that still have high cathode emission (70% +). They should be advertised as such and sold at a reasonable price! Certainly not for hundreds of dollars!

I bought a used quad set of RCA 6L6GC black plates for use in my Fender Twin. $75 per tube ($300 total). I consider this a good and fair deal. The US - made Black Plates are the ne plus ultra's of the 6L6's (for tone and longevity!).

I suspect that some of these "NOS" 6SN7's (and others) may be used "pulls" in old boxes!

It's very common to have nearly new tubes sold as NOS. Test measurements should be included with all tubes.
  Also, a TS 6SN7GT or GTB from the 1950s or 60s should be very affordable.

Here is an accurate guide for NOS tubes...
http://www.audiotubes.com/6sn7.htm

When I bought my Freya I just ordered the stock tubes and then went looking for something else that could help improve the sound at a reasonable price.  Let's face it you probably don't want to spend more for the tubes than what the preamp cost.  You definitely do not want the LISST if you want the sound of tubes. I had already tried the Early Russians in an Atmosphere amp that I have and found them to be a very good bang for the buck tube.  Better than the Tungsol which I have also tried.  I'm sure the Tungsol tubes Schiit sells are matched and a good value, but IMO they're probably no better than what you can find elsewhere (Upscale Audio for example), and again the Early Russions are much better for only $5 more.

I have no experience with the tube lowrider speaks of but but kinda doubt that's what Schiit is selling.