There is no simple answer to this. I would suggest you reatin an attorney to deal with multiple problems your son faces, It is quite possible that your son, with the help of an attorney might be able to find some alternative sentencing to deal with his drug problems which apparently is he root of all of his issues. The judge could sentence him to jail.
These are extremely serious charges. I ran a Florida Guidelines Scoresheet calculation on his sentencing range (without the inclusion of prior offenses). The lowest permissible sentence is currently set at 40 months, with the maximum sentence set at life in prison. Understand that the State Attorney's Office may agree to reduce or modify the charges or the sentence based upon mitigation, i.e., proof that he has a substance abuse problem and is taking steps toward admitting himself into treatment. An attorney in your area should know who to contact about getting an evaluation for your son if he is in jail. Also, your son should start going to NA meetings every day, even if he is in custody. If your son is out-of-custody, he needs to demonstrate that he can remain drug and crime free. Get him tested confidentially every week and get those results to the attorney. The attorney will look into other departure alternatives, such as youthful offender (if your son is under the age of 21), or mental health departure if he suffers from other mental health disorders. If your son is turning 21 soon, it is imperative that you let the attorney know so that he can set a change-of-plea hearing prior to his 21st birthday. On a different note, how did the police get authorization to search the residence? A good attorney will investigate possible defenses without burning any negotiation bridges. This being your son's first criminal episode, he might be able to persuade the State or judge to impose a non-state prison sanction. Follow the recommendations of the attorney.