RE: What aircraft did Quique use to win the F3A Championship?
Not likely as my understanding is that Oxai has the resale/kit rights for the Euphoria.
It has been that way since the start of kit makers based upon the designs of others (and usually winners of one or more major championships).
Way back you could purchase the plans and create your own. I am not aware of that possibility on the more recent designs.
From what I've seen of Oxai construction the regular modeler-builder (not ARF assembler) would have a hard, hard time matching the light weight construction techniques.
Today it isn't easy to come up with true contest grade balsa, much less the experience necessary to fabricate the structure.
On Pattern A/C the low volume levels make it very hard to offer the planes AND make money. The necessary numbers simply aren't there.