What are some good MTG cards for a blue artifact EDH deck?

Im running monoblue and my general is arcum dagson. my strategy right now is using artifact tokens to get out darksteel citadel, whispersilk cloak, and fireshrieker, then equipping those to either blightsteel colossus, or phyrexian juggernaut. i have tezzeret the seeker and master transmuter. what else can i put in this deck to get out colossus and juggernaut faster?