Looking to purchase a new envelope printer(s) for printing A2's to 9x12's. Quantity up to 500,000 per month. Quality needs to be excellent - low to heavy coverage. Speed is important too. Any ideas on where I should start to look? We are evaluating Quadient Mach7 now but would like to look at other options. We currently have 2 Quadient Mach6 and 2 AS-850s in our mailshop.