In general, your plan seems sound.
In specific, your personal safety should be your paramount concern, since you are planning on the initial screening meeting solo.
Choose a very public place. Avoid disclosing too many personal details (last name, address, phone number) - if things don't click or the guy turns out to be a problem, you want to avoid having him follow you home, or stalk you. Have a plan to visit a number of different locations after the meeting, before you return home or to a place like work, also public venues with lots of people traffic.
Having done this for a while, if you elect to meeting him for the "real deal" encounter, use a hotel or motel, not your home or apartment. Leave your valuables locked in the car, and take only the minimum you need into the room.
The rest is free-form, up to you, primarily, and your husband, secondarily.
Be forewarned that there are many men who have this fantasy - realizing it is something different entirely. Seeing your wife take another man's cock the first time is incredibly intense and emotional, even if your husband has been fantasizing about it for years.
Also be prepared that "online guy" make flake out, and fail to appear at the initial screening meet, or even for the "real deal." Hard though it may be, don't take it as a sign of rejection, or be terribly disappointed about it. Flakes/no-shows are the number one biggest problem in this.
Good luck.