My station equipment
In order to get started with amateur SSTV any SSB-capable communication receiver (RTX, if you are going to transmit) along with a good installed and matched antenna will do the purpose. It's the basic hardware to buy somewhere at affordable price if you're thinking to start from scratch. I'd suggest you not buy a commercial rig interface, it's about a small piece of hardware you can easily build yourself.
My all-mode interface is opto-isolated and includes a switchable mic preamp with PTT control input; I built its CAT module around the MAX232 IC.
So, in my shack among other things I have a Kenwood TS950S Digital, a TS940SAT, a TS140S. I also have a Yaesu YO-100 (Monitor Scope), an antenna tuner, a Daiwa CN801HP (SWR/PWR meter), and a homebrew AFSK/CAT interface for digimodes. In addition, I chained some outboard rack units from Behringer along with a tube preamp and a condenser studio microphone; all gear is used in conjunction with my TS950 in order to shape audio, enhancing fidelity by extending transmitted audio on a 3100Hz max bandwidth (eSSB 3K00J3E). Computer is AMD A4-3400 running GNU/Linux and Windows 10 64bit with 8GB of RAM. I also have built a 1-meter mag loop which is mainly used for reception in high QRM situations and have raised a 5/8 wavelength vertical antenna at the very top of my roof, about 90 feet above the ground.
HRDeluxe by Simon Brown, HB9DRV has Digital Master, powerful logging features and much more. Starting from v6 the software suite is no longer available for free.