I considered this option for one of my TS-830s some time ago. After a good deal of looking around I came to the conclusion that the LP-PAN (
http://www.telepostinc.com/LP-PAN.html) was quite a good option compared with the el-cheapo SDR dongles. There may well be other options now.
There are a few things to consider and about which you can google some commentary. First, the 8.3 MHz IF output spectrum of the TS-830 is inclined to present a lumpy baseline which can be minimized by appropriate mixer loading and a few other mods which I can't fully remember. You'd think that some of the SDR software packages would allow you to normalize the spectrum to a reference and remove lumps and bumps in software. However, at the time I was looking I didn't see that readily available in the packages I'd consider.
Second, the SDR software needs to be tolerant of having no CAT control available to the old TS-830. Some newer software versions get upset if they don't see the control option in place. However, I'm sure that with a bit of looking and playing you can find something that will work.
There is of course a panadapter option (BS-8) available for the Kenwood SM-220 monitor scope. However, unless you happen to have an appropriately equipped SM-220 ready to go, I'd say don't waste your time. The feeble, drifting spectrum and small display is a poor specimen by contemporary standards.
In the end, I didn't proceed with the bandscope option for my TS-830 but I'd be interested to know what path you decide to take. I still use the (decked-out) 830 quite a bit, despite having lots of other radios.
73, Peter.