Numark Mixtrack (Pro)
I’m planning to buy some of the Mixtrack controllers, as I could read the PRO has built in soundcard. I have an external sound card (not professional one) http://www.sweex.com/en/assortiment/sound-vision/sound-cards/SC016/
So please if anyone has a good knowledge to tell me what to buy, the usual Mixtrack or the Pro one.
Thanks, 
You could probably get away with using that soundcard, but I don’t know what the performance of it would be like. For the extra £40 I would probably just buy the Mixtrack Pro, as it has the soundcard built in and will be less hassle/cables to set up.
I’ll admit, I had the mixtrack without the soundcard to start off with, using it with my desktop pc and a 7.1 internal soundcard. It worked, but it was a pain to set up, working out which outputs on the card correlated to the software was a nightmare. Performance was ok, but nothing like it is now (I now have a Denon MC6000 with built in soundcard).
Or, for an extra £20 again, you could get the basic mixtrack without a soundcard, and then get an NI audio 2 and full traktor 2.5. Bearing in mind that neither of the controllers come with the full version of the software, this seems like a bargain, essentially getting the soundcard at under half price!
Link here: Buy Numark DJ Equipment Online | DJKIT®
Although it depends what software you want to use. The mixtrack pro will work with serato intro, where as the normal mixtrack wont. They both work with VDJ though.
Go for the mixtrack pro right away. A year or two ago I would’ve suggested going for the Mixtrack with a separate sound card, but if you ever choose to upgrade, it’s most definitely to a controller with already built in soundcard.
Robdquick’s point is a very valid one though… but by the time you want to upgrade, you’ll probably still get the full version of the software associated.