Save for Gears 3, unless you want either, in which case go with Dead island. You'd be getting a Gears of War clone, if you want Gears of war, go with the original series, not the Warhammer 40K edition.
By the way, I'm not the biggest fan of warhammer 40k, the concept is there for me to like, the execution fails. The helmets of the armor look cool but when I see power armor, I expect it to protect me while still allowing me to move, such as the MJOLNIR armor from Halo or the Nanosuit from Crysis, or even the Dead Space Engineer/Security/Advanced armor. Also, the whole Mideval warrior with tech thing is cool but the Elites from Halo pull that off in a much better fashion
/End rant
In short: Go with Dead island or save for Gears 3.
By the way, I'm not the biggest fan of warhammer 40k, the concept is there for me to like, the execution fails. The helmets of the armor look cool but when I see power armor, I expect it to protect me while still allowing me to move, such as the MJOLNIR armor from Halo or the Nanosuit from Crysis, or even the Dead Space Engineer/Security/Advanced armor. Also, the whole Mideval warrior with tech thing is cool but the Elites from Halo pull that off in a much better fashion
/End rant
In short: Go with Dead island or save for Gears 3.