Both are extremely good. But I would go with Enshin, as full contact sparring will give you excellent stamina and conditioning for a street fight. You will also get use to pain. And the grappling side of Enshin will be very useful on the street and should be easy to learn, as you have previous experience. Not to say Shorin Ryu doesn't have grappling though. You may also get the chance to compete in the Sabaki Challenge What ever you decide Im sure you will be pleased. As Shorin Ryu bunkai is top notch for street defence. Even though Kyokushin is mainly Naha Te. I prefer Shuri Te katas as they contain more street/self defence moves.