None of the personal cosmetic items will give you any advantage in the game.
They will not change any gameplay mechanics or otherwise give you an advantage in the game.
Excerpt from https://www.bohemia.net/monetization DayZ Server Monetization From December 1st 2015, anyone who registers, is approved, and is listed on https://www.bohemia.net/monetization/approved/dayz is allowed following monetization of their Dayz “private shard” servers: Charging players to access your server, if the fees and associated perks do not affect gameplay in any way, is allowed. Limiting access to only paying players is allowed.
Servers with access limited to paying players must be on a different hive, or have rules and settings identical to the freely accessible servers. Product placement, in-game advertising and sponsorship is allowed.
Accepting donations is allowed, but to avoid any doubts: not providing donations must not prevent anyone from accessing the content.
Selling of in-game items, that don’t affect gameplay, and selling of cosmetic perks are allowed. (Applicable only to servers with mods, after modding support has been added to Dayz) Please remember, that these rules do not apply to public hive Dayz servers or the Dayz mod! If we feel anyone on the list at https://www.bohemia.net/monetization/approved/dayz is exploiting any loopholes or is not acting in the best interests of the community, we will remove them. That will mean they will have to cease this kind of monetization immediately or face legal action.