Looking to replace stock radio with something different; nothing special, just a little more up-to-date. Have 98 Disco...anyone know what type of adaptor I will need for an off the shelf stereo? Does it depend on the new brand or all they all standard?

 

Do a search in the forum, there have been a few threads already about the types of adapter harnesses etc that you would need. There are two options. you can either continue to use the pre-existing amplifier by buying the adapter, which im sure you can find a link for if you search, OR you can rip all the speaker wire out and run it yourself (the way i would probably/ will probably do it).
The issue, in case you dont know is that the current head unit isn't powered, so all the speakers run to an amp beind the passenger kick panel and then from there, it goes to the stereo. So in order for you to hook up an aftermarket (powered) head unit, you need a way to interface with or cut out the amplifier.

 

i did this when i bought mine, your gonna want to run all new wiring to the speakers, not a huge task in these trucks since you've got plenty of space to work, then you've got pretty much a clean slate when starting off and you'll know you won't run into issues (assuming you know how to do it right haha)