best bet, find a boot that fits, and find out what its freestyle counterpart is.
aka nordica best... is the same as the spark and ignition boots, they just have freestyle specific features.
salomon foil is an impact. spk is an anomaly onto itself.
tecnicas agent line of boots has no freestyle specific features, just a common colorway.
atomics high rolla corresponds with a different boot in their line based on the flex index.
im too tired to think of what else there is, but theres a few. personally im gonna ride fulltilts this year. clean foward flex, intuition style liners, and shock absorption. i have a narrowish foot, and can fit into a 98mm lasted boot. from there i know i can punch, grind or pad to get it right. the boots i rode last year had 20 hours worth of labor put in, but they were too wide in the toebox from the start.