Since you hold a Class B license but haven't set up shortwave communication, you won't be able to take the C exam, so your immediate priority is to purchase a properly approved and functioning device.
The most cost-effective options are the portable FT-891 and the larger IC-7300.
When new hams start with shortwave, I recommend starting with a 100W transmitter rather than immediately using QRP (low power). This can discourage beginners.