With it being September 27th, I think you are overly concerned with availability.
I’m not saying don’t be concerned, it’s just that you are still ahead of the curve.
Stuff should start showing up over the next few months.
The FTX you got from REI is most likely left over last year’s stock.
Some regions or vendors may get stock sooner than others, but I would bet that right now, they are most concerned with getting rid of summer stock, with winter stock on its way.
Have you said where you are skiing?
Based on what you want, the FTX sounds like a good choice.
If you’re sticking with Asnes, you could use the Mountain Race 48 for the track focus.
But it may be hard to find.
https://www.en.asnes.com/produkt/mountain-race-48-2/
Other than the Mountain Race 48 or Mountain Tour 51 I don’t think Asnes offers a ski that will work well in a groomed track. The tips will be too wide.
Generally, tracks are 70mm. The Gamme tip is 68mm, so would fit going straight (although tend to rub and drag), but will hang up in the turns, and send you out of the track (they want to go straight).
For the in between ski, many here are not happy with the Asnes waxless skis — not enough traction.
Based on posts, the Nansen waxless seems to get the most positive reviews, but still somewhat lacking.
For the in between ski, it sort of depends on what you want from that ski. Maybe you just want an all around ski, that’s not going in a groomed track, and you’re not expecting great turning, but can do pretty much anything else, to some degree.
Just my two cents, but if you are set on a waxless ski, you might consider the Fischer Traverse 78 for the in between ski (they get generally favorable reviews). The Traverse 78 is just about the same width under foot as the FTX, but has a much narrower tip and tail.
Another option is to go with something like the wax version of the Nansen, and just leave a 30mm mohair skin on most of the time. Not ideal, but I have been impressed with the glide I get with a 35mm skin on a Gamme (which does have more wax pocket camber than a Nansen, so the glide with a skin on the Nansen may be less).
Hope I have helped more than confused!