BIG IP 2000 migration to i5800 vCMP

Hello folks,

Would like to know what challenges do we face while migrating BIG IP 2000 series HA pair to i5800 vCMP? To explain the scenario, we are migrating from two HA pairs of F5 2000s (One running APM, ASM & LTM modules and another unit running LTM module only) to a single i5800 vCMP pair which will host these two sets as guests running over different versions and modules. What approach do we need to follow? Can we restore the UCS from older units to the newer ones? We are going for Like-to-Like migration as far as the applications goes, do not want to go for a BIG BANG migration. Looking for some inputs considering the challenges we might face during this migration? What prep work needs to be done before the migration to avoid issues during the migration.

Thanks in advance.