Yeast wise, I'd say 1116 or cote de blanc are great choices, if you're looking for a less acidy mead, perhaps 71B-1122. I'd say hold back 1/3 of the blackberries to add to secondary, to give you more fruit on the nose and more true-to-form blackberry flavors. Remember that fruit is greatly changed flavorwise during fermentation.
Primary:Russian River Redemption clone, Kelly's Melomel, Graham's English Cider 22-23
Aging:Public House Dry Stout, Procrastination Porter, Mr. Brown Ale, Westvleteren 12 Clone, Mead, Duvel Clone, Graham's English Cider 6-21, Belgian Draak Strong Ale, Fig Melomel, Acerglyn, Restorative Tonic Metheglyn