You can fit any double din sat nav or entertainment unit into your Antara and no you will be much cheaper going to a local auto electrician or even better get a mobile one to come to you. To be honest most dealers subcontract this type of work anyway.
Im also not a fan of the position of the sat nav screen given the choice a tom tom would be a better option with a cheaper head unit for music and bluetooth for your phone calls if thats needed.