Not old fashioned at all - Bowie was wonderful. We're in the UK (about a mile away from where Bowie grew up, incidentally) so the rap has a bit of a different sound than in the States. There's a sub-genre called grime that's particularly popular at the moment. It's kind of a hybrid of rap, drum 'n' bass, hip hop and afrobeats. You might like it if you're into cross-genre music
Lots of quite clever lyrics and wordplay amongst both the secular and Christian stuff. I'd recommend Guvna B, Victizzle, and Faith Child as Christian artists, or Tinie Tempah, Wretch32 and Skepta as secular ones. The London accent might take some getting used to though
What's the rap scene like in Australia?
And (shameless plug!) this is my brother - this song's a couple years old but it's still one of my favourites, lyrically.