I have owned one Orion motor and I considered it to be poor quality (a.k.a., junk). It is possible that the Formula SV2's are better but I have never used one.
I will make a suggestion that I have made before to others with similar questions: Find yourself a good used (or even new) "ARCOR" 19T handwound motor. The ARCOR handwounds were very popular about a year ago, but the organization folded and very few people run the 19T handwound motors any more. But racers have loads of them laying around. One that was one tenth of a second off the pace for a serious oval racer will still be better than a cheap mod 15T. I have seen two brand new ones for sale recently on hobbytalk (www.hobbytalk.com
) for like $20 (http://www.hobbytalk.com/bbs1/showthread.php?t=212639
). A good 19T handwound will easily be more powerful than a mediocre quality 15T motor.
I think so highly of these that I am not even going to offer to sell you any of mine. I like them too much. But I am sure you can find some good ones for good prices. If you buy a used motor, be sure to ask about the com size. For best life, you want want that has not been retrued too many times. That translates to a com size of .285 or larger.
If you can't find an ARCOR handwound, you will do just about as well with a 19T machine wound motor like a Chameleon or an Ultrabird. Do not get a Komodo Dragon - they are high RPM, high current draw motors meant for racing and will require much more maintenance. I can sell you new Chameleons or Ultrabirds for $20 plus shipping, but try to find an ARCOR motor first.