RC Country as mentioned above bought out Quasar One and still sells the products on their shelves but I'd not expect there to be any new designs forthcoming. I don't know if they're doing any mailorder sales but it never hurts to check directly.
Here's the link to their website with contact information...
Uh oh... DO NOT ATTEMPT TO VISIT THE RC COUNTRY WEBSITE AT THIS TIME!!
According to OpenDNS and Google it appears to be infected with malware at the moment. I will let the owners know their website has been compromised and tries to install malware from three separate .ru domains.
In the interest of full disclosure, I am personally acquainted with the family that owns RC Country and Quasar One.
Cranky Kong, Certified Rocket Monkey
"We were promised jet packs!"
Total Impulse in 2016: 1,318.99 Ns (Equivalent to a 3% K motor)
Total Impulse since 2010: 12,338.57 Ns (Equivalent to a 20% N motor)