As stated by others buying in-game items (such as the Juggernaut Suit in this case) is not offered by the server but by the players that play it. What the servers offer is life-time VIP that gives you in-game benefits and access to more features, as well as booster packs which you can buy in singles or bundles that give you in-game benefits in terms of wealth. I believe his VIP is already set up but here are links to buy both VIP and Booster Packs offered by the server:
zarpgaming.com/index.php/zarp-vip
zarpgaming.com/index.php/zarp-vip/booster-pack
EDIT: I would also like to bring to your attention all in-game items that are equip-able on your hot bar, including special suits, are in risk of being lost if you die having them equipped. One of the strategies in-game is holstering these items into your inventory to avoid losing them when being killed (/holster in chat to holster directly.) Suits cannot be holstered rather need to have a config file to equip and de-equip them using a bind or manually doing so via F4>Inventory