They dont actual sell the concept 600 anymore. Was replace by the G5 Concept 650.
Had this installed on my car and no problems at all, with intelliastart.

You can also add any module you want after installation i.e windows up, jacking sensor etc. So you dont have to weight out for it all at once.

but just make sure the fitter is confident to carry out the work.

Where abouts are you Tabetha?