"Beats and Mashups", hmnn for that specifically I'd go FL Studio between the two. Having said that, Pro Tools is an industry standard. Acid would have to be thrown in to the discussion for Mashups, that's what it's designed for. I guess the way I look at it, why choose? Learn em' all and use the tool that works best for the particular job at hand. I wouldn't dream of limiting myself to one guitar, why would I do that with software?
I don't believe in the "learn how to do everything in one program or your not serious" philosophy. Adobe After Effects does certain things, Vegas does certain things, Photoshop etc, no film maker would use only one program to make a movie, no Graphic Artist would, not someone doing 3D, it's curious that musicians get hung up on the "only one program" thing.
But... taking the "I'm a beginner" thing into account, go FL, you'll be making beats in no time.
Although Reason is great for teaching you terminology that everyone else uses. as opposed to "Fruityspeak" and will also have you making beats in no time, but Mashups, don't know how you'd do thtat in Reason so... FL. So many good tutorials for FL, NFX has got some of the best. Personally I couldn't imagine any version less than the one with audio recording but... you could go with the Piano Roll version if your not gonna be recording audio any time soon. That link NFX put there will give you discount on upgrades later too... btw.