viewtopic.php?f=1&t=20365&hilit=3x3+speedcubeThat's a recent thread that is similar to this one.
Basically there are two sides of the argument.
side 1: You should get a cube that is only a little bit better than a Rubik's (type A or F) so that you don't start turning wildly
side 2: Go ahead and get the one of the best cubes on the market (Dayan Zhanchi or Dayan Guhong) so that you can get the most out of your solves now.
Or just get several cubes and see which one you like best.