How to upgrade my djing?....?

I've had my dj setup for about a year with serano scratch live on my laptop.


I've wanted to get into producing for awhile and I've resently tried out logic on my friends mac.


I've wanted to upgrade my laptop so I'm buying a mac. What mac would be the best at running serano scratch live, logic, ableton and virtual dj? I was thinking a 21.5'; iMac or a macbookpro.How to upgrade my djing?....?
Never buy Mac. A Desktop from Walmart with Windows already installed is better than ANY MAC ANYWHERE even when updgrades.