It is preferable to find a sincere and scholarly person who is careful about keeping the mitzvot to lead the congregation for Slichot and the High Holidays, someone who is married and over thirty, and humble as well. All kinds of Jews are potentially suitable for the role, but the congregation should approve of the choice. If he has an enemy and intends not to include him in his prayers, then no-one can fulfill their obligation through him, even if they are his friends.