Hi. I'm currently using Airport Extreme connected to an external hard drive (4TB) for backing up using time machine..but since we thought that the hard drive is not enough due to increasing of file size used by my co-employees, we though of upgrading.. so my question are.... can I use Airport Extreme connected to an external hard drive + Airport Express also connected to another external hard drive? Or should I buy Airport Time Capsule and connect it an external hard drive? (if it's possible) Or is it possible to connect 2 external hard drive to 1 Airport Extreme? Thanks in advance.