Laptop for live rig

[Herman Munster]

I've used a Motif ES8 live for 5 years now and it's time to upgrade. My VSTi's over the last 4 years have grown a great deal and I am now beginning to realize all the areas where the ES falls short. I'm considering going with a controller like the KX8 and a laptop live. My current VSTi's I run in the studio are: Ivory, ArtVista Virtual Grand, Komplete5, Reason and several more. My wife has an old Mac Book and I'm considering using a Mac Book Pro live. Here are my questions:

1) Will I need any additional interface for live use with a controller? I'm more concerned about audio output as I know the controller will use USB for MIDI data.
2) Are there other issues with live use of these VSTi's I haven't considered? I use a PC in my studio and occasionally have issues with my processor "choking",but that's in Cubase with multiple plug-in's, etc. running. I'm assuming this should be much smooth with the Mac Book.

Thanks for any opinions.