Keep in mind the rules and equipment for this rpg system is apread out over a score of books and 4 different sub-games. Of which deathwatch is but one. The rules for mechandrites are listed in the Dark heresy and rogue trader books.<br/><br/>And in dark heresy yes, the tech preist starts with one on his choice, but no servo arm. You are a techmarine and not a martian priest. Your atarting equipment is not the same. As for getting one. You basically have to ask the gm once the game starts. Maybe acrue some requisition points first via this first mission.<br/><br/>I believe the Only war books mention the various models of mechandrites as well.<br/><br/>I will also add that to use that mechandrite, especially alongside your aervo arm, you will likely need to get a servo harness first. Which is only something you can get at a higher reputation if I'm not mistaken