First off, don't judge me for my POS PC I use for radio. So far it's been good for 8 years plus.
It's a Cyrix III / Via C3 / centaur what ever you wanna call it running at 800mhz with no L2 Cache, running Win2k as the OS. It's a dog and half. But only 40 watts at full CPU/GPU at the wall, can't complain.
I use MixW 2.18 for my PSK/RTTY needs. Even using this POS PC, I've had few issues. PSK decode is great as is the RTTY. It will even auto track if you are a few hz off. Does Hell, OLIVIA, ROS, SSTV and many other modes. For free also. But when you change modes, you have to wait 15 seconds, that's the trade off for free. Under good conditions and if they have a clean fist or using a keyer, the CW decoding using Mix W is more than passable.
MultiPSK seems to work pretty good, but that is the WORST UI imo of any software on earth. Seriously.
CW Skimmer is more than decent for just CW.
If your not going to transmit, the setup to the PC is cake. Just need to feed the radio audio to the PC input. No other cables needed for just decode.
Hope you find something that works well for you.