There are a number of ways to run an Internet radio station, and as such, every DJ’s needs will vary. That being said, you will likely want something to have some tactile control over your tracks. You will find that you will be more comfortable with a DJ controller, not least because it’ll allow you to use headphone monitoring.
This is why many DJs will want to consider getting an all-in-one DJ controller (also known as a MIDI controller, though that’s not always 100% true). Lucky for you, many of these units can be had on a reasonable budget.
I recommend a 4-deck controller if you’re using standard DJ performance software such as Virtual DJ or Traktor. This allows you to have two decks for music tracks, and two decks for samples, jingles, drops, or whatever else you want to plop over your music tracks. (Note – that means that something with sampler pads can be useful!)
You may want jog wheels if you’re going to do club-style gapless mixing, but if you’re going the more traditional radio route, this may not be necessary for you. Something like the Novation Twitch becomes more appealing if you’re not looking for a “turntables” feel.
Most controllers these days come with audio interfaces (sound cards) built in, but you should make sure that the microphone input actually routes through your software and doesn’t just go straight through your main output. This is because you will likely be broadcasting digitally via your computer, and you don’t want your voiceovers to go to your main outs instead of your computer!
There is no clear cut answer on which is the best DJ controller for you, as it depends on your own style and how you want to play. The beauty of the market as it stands currently is that there are a lot of options! DJs can finally choose how they want to perform without being wedded to a single “industry standard” and creatively express themselves through whatever interfaces they want.