Criminal Law Questions? Ask a Criminal Lawyer.
with the background information that you are providing, i would venture a guess of probation with a suspended sentence and as long as he completes a rehab successfully he will be okay. now, here is what you should consider. get some names of inpatient rehabs in your area and try to secure a bed for him. the problem often times is a court will order rehab and then the defendant needs to sit in jail until a bed is available. so try to get working on that. get a letter from them showing that a bed is available. his attorney or public defender can use that to show the prosecutor and work out the deal on the sentencing.
it is clearly apparent that he needs inpatient treatment. good luck with everything