jvs, Your blend of berries sounds good to me. I grow red, white, black currants, blackberrries, red & black raspberries,beach plums, sand cherries, chokecherries, chokeberries ( aronia ), blueberries, josta berries all for wine making.
I mix them in various amounts and make different blends every year depending on how many I get and I think most red fruits and grapes go together well.
I differ in my tastes in wine as I make all of my wine very dry, most people like there fruit wines to have a little residule sugar as it makes the flavor of the fruit distint.
Jedman