The LX would probably be a good choice. There aren’t really any tricks up to level six that are very stressful on your unicycle, with the exception of hopping standing on the wheel. I messed up my first unicycle, a Torker CX learning it.
Judging from the pictures, the Dube unicycles would probably not be a good choice. The saddle looks really uncomfortable, and the wheel and frame don’t appear especially strong or good for freestyle riding.