I know some people are huge LibTech NAS fans, They arn't symetrical but ive heard really good things about there versatility. Other then that, everyone on here is a huge dan of the on3p jefrey's. I still don't think they are 100% symmetrical either.
I must agree with boax. You will want more then 1 pair. But if you go for one look for 100-110 underfoot, rocker tip and tail with some decent camber. It won't be good for park but you don't go to whis for park.