I like the F-8 Tomcat Slalom fins by Tectonics. I have the 42 on my iS 111 and use it for 8.5, 7.6 & 6.6 sails. NO spin out and if you do push it out, it immediately pops back without pulling the tail of the board back in.
They come in sizes from 38 - 44. Less expensive than the Debs.