Cheap Midi Controller Or Synth Controller? Options

[the clash]

After months of research, decision making and saving I have decided to go the soft synth route and start off by purchasing Logic Pro 6, Reason & a Midi Controller.
The only thing Im not sure about is the quality of these Midi Controllers, they look a bit cheap and look as if they wont last very long.

I don't want to pay for an expensive keyboard with many sounds & sequencer especially if I will be using Logic & Reason.
Would I be better off paying a bit more money and purchasing something like a Alesis Ion or Novation KS4 and using one of these as a Midi Controller?
I know these are probably not up to the build quality of something like a Korg Triton for example but I feel they would be better than a cheap Midi Controller.
Please help! (£500 is my budget)

Cheers.