Yerlo,
The Yorkshire -200 sim is excellent. They have carried out loads of training for assessments for Ryanair and others and it is relatively great value and good tuition. There obviously are differences between the 200 and NG but during the assessment all the automatics are turned off and the instrument panel is re-configured which reduces the differences significantly.
virtualflight also looks like a potentially good option (I have never used them) it is an NG. It is fixed based so keeps the cost down.
Or bite the bullet and shell out for a full motion NG sim but you are paying a lot more and I don't believe it is worth the additional cost at this stage.
Good luck