Matrix Aurora is the just make and model of the rim, not the hub. Most likely, your original wheels came with Shimano Tiagra hubs. Check the markings on your front wheel hub if you still have it. If it says Tiagra or Shimano 4400, then it's definitely a regular cup and cone hub using loose balls. If you have Adobe Acrobat reader, click on this link.
http://www.shimano.com.au/publish/co...-4400-1861.pdf
I agree with Nessism. Loose ball hubs are easier to work on. With sealed bearring hubs, you have to completely replace the cartridge bearrings. That's not tough if you have a bearring puller and know the particular type of cartridge bearring replacement. But water will affect any hub if it's ridden in the rain frequently.
If you're planning on learning how to build up a bike you should learn how to disassemble and replace balls on hubs. Balls and cone wrenches are all that's needed and they're cheap.