Connecting Pepwave Surf SOHO MK3 to ADSL


I am going to buy the (Pepwave Surf SOHO MK3) but i have a ADSL connection

is the only possible way to connect is through bridged Adsl router ??
or can i use usb modem to convert the rj11 to rj45?
or is it possible to connect throw a pci modem ?