I believe the Kaiju is the next step up in stiffness from the Vapen. I have a few friends that wear 32 boots and they love them. But you need to try on as many pairs of boots and brands that you can to find the perfect fit.
The Kaiju is the best boot I've ever worn. Only other boot that even comes close is the Burton Ion. Don't skimp boots have a bigger impact on your riding than the bindings or board in my opinion. Thirty Twos are decent but not in the same league.
I bought a pair of ThirtyTwo Focus Boa's at the end of last season and the fit is awesome - no more heal lift. They aren't any more comfortable than my old Burton SL10's but they aren't uncomfortable by any stretch.