Havent compared the two, can give you my thoughts (I have used the torquay freerides for 7? years). I looked at the supercross yesterday, looks like a beautifully presented fin, it is a little narrower than the torquay or at least has a more progressive thickness variance. So probably should be a little quicker and shouldnt have to start quite so far off the wind with them.
I believe the torquay freerides are too thick towards the head of the fin, also the torquay will stick and stick and stick but when it lets go it's when you are at your most compromised resulting in a bad stack. The torquay is not a great fan of cranked over gybing and will spin out in the gybes. The supercross has a more progressive flex too... again down to the pretty large thickness variation of the torquay.
At the price the torquay's are hard to overlook but my general impressions are kinda like this- imagine the torquay is a holden/ford, fine for most people. The select is more like a bmw/merc, if you had the money you'd probably pick it over the locally produced model.
It's a pity the select's go under the water cause they really are a fancy looking fin

. Dunno about being available in us box though- another thing quite a few local people have mentioned to me that they've lost their torquays- they develop a whitish weak spot near the base and eventually they let go.