For cables, Nando, Vintage King's in-house label DB-25 connector snakes are good (I think they are manufactured by Pro-Co). The link is for a 5' snake but you can buy other lengths: Vintage King DB-25 to xlr snake
You'll also need these balanced xlr > unbalanced rca adapters
if you're trying to connect to your unbalanced stereo gear.
The best solution in my mind, however, is a 16 channel mixer much like my Mackie 1604
where you can plug in all 16 tracks and mix down to the two channels going to your stereo(s). Buy two sets of the DB-25 > 1/4" TRS (stereo)
and plug everything in to the 16 line inputs on the mixer. If you're planning to record multiple albums using 2 tracks per album, that would give you 8 albums per tape or 4 albums per tape if you have a full-on quad setup with quad albums. Using a mixer to access these tracks as needed is a lot easier than constantly patching and repatching cables depending on which 2 (or 4) of the 16 tracks you've recorded. You don't necessarily need 16 mic inputs - that just adds cost - but you would need 16 channels each with a 1/4" line input jack. This Yamaha MG-16
is the most cost effective way out there to do this. Keep an eye on CL for older versions of the 1604 VLZ Mackie or the MG-16 Yamaha. They can be picked up pretty inexpensively. make sure theycheck out thoroughly, though. These things tend to take a beating if they've been used by a band.
Edit: the issue with either of these mixers is that they don't really have 16 line level outputs that can redirect audio from a source other than a microphone back to your DA-98. The Mackie has 16 direct outputs (one on each channel) but those are pass throughs from the mic inputs only. If you want to send a signal from your stereo to the DA-98 through the Mackie, it goes through the buss system, and there are only 4 busses. The Yamaha is worse - it only has 2 busses. You could use a Y-adapter on each of the 4 busses on the Mackie to get to another 8 channel DB-25 snake going back to your deck but that's about all you could do without moving the DB-25 input connector to channels 9 - 16 when you need them.
And as you can see, none of these options are particularly cheap. Those DB-25 connectors will mount up quickly.