Do not lie to your landlord, even by omission, or attempt to hide your snakes. I ended up with a free retic b/c someone else tried that.
In addition to looking for apartments look for roommate rentals. A homeowner who rents out a room and who permits pets may be more open to a tenant having a snake as long as it's kept in your bedroom. If you feed f/t plan on keeping a small dorm-type freezer in your room for the rats.