I am looking for a job opportunity in the US. I am Australian and can get an E-3 visa with sponsorship. I am looking to live and work in the US for several years, ideally 3+. I have a wife and 2 kids and we would like to experience life living and working overseas for a time before the kids are older.

I am having trouble finding a job or getting any responses to my applications. I understand it is more complicated hiring someone who needs to get a visa and if an employer was presented with 2 similar candidates, one requiring a visa and could not start for 4-8 weeks....

So i am here asking for some "boots on the ground" info.
What is the job market like in the US presently?
Does anyone know of US employers hiring Au/UK/NZ/Canadian employees?
Is it common?
Would anyone recommend acquiring a SPED certification (Piping Designer II)

If anyone is looking for a piping designer I can make my resume available. Briefly, I have 7.5 years experience designing skid packaged equipment from 5 to 75 tonne, Associate Degree in Mechanical Technology, 7.5 years exp. with CADWorx Plant 3D, Navisworks, CADWorx administration exp.