The Accucut company always offered some dies that you could use for quilting, but their main business was paper craft. Several years ago, Accucut split into 3 separate companies: AccuCut Craft, Accuquilt and their custom die group.
The Accuquilt Studio and AccuCut Grande Mark are the same machine with different decals.
Anyway, one big difference between them is that AccuCut Craft has WAY better sales. For instance, right now the quilt side has 35% off some dies, while the craft side has 50% off all dies. The craft side doesn't have the dies that are specific to quilting, like strip cutters, but if you do applique, they have lots of shapes. So if you are into applique or wanted to cross over into paper crafts (cards, boxes, bags etc.), now is a great time to buy.
Not sure if the cutting mats are included in this sale, sometimes they are. I always stock up when they go on sale on the craft site.