Everydisplaynameistaken

Hi all, looking to migrate in 2018 from the uk. I realise this may slide to 2019 with legalities. I am looking for advice on wether it is simpler to go down the route of sponsored migrant on a business visa (457 from memory). Is it worthwhile to start the legal process before seeking employment or is it the employer that must request the visa and instigate the process? Perhaps it is better if someone recommends a reputable visa service to advise or even a reliable recruiter that people have worked with internationally. Mid management / sales. Within construction / commercial property. Appricate this is chicken egg / cart horse. Assistance greatly appricisted.