Most staff tend to have variable stats that change, so if you can't get these people then simply search for an ***. Man using Scouting Potential Scouting Current Ability, Motivational (good for helping with team-talks), Discipline (I think this helps with keeping your players in line), and Tactical Ability (important if you want to have your ***. man do all the pre-match player tactical assignments). For general staff just sort by Determination, Motivation and Discipline and pick the best staff with the best training attributes (GK, attacking, def, technical, tactical) and they'll generally be 4 to 4 1/2 stars (GK and fitness coaches should be numerous enough for 5 star quality). The best staff in the world generally tend to be in Brazil (including Ruben Sosa if he rolls a good discipline stat), so you should enable that league to get their staff.