Help with a chili recipe: need help on fruit/sweet selection
Traditional Cincinatti chili calls for half a square of grated baker's chocolate.  I don't know how set you are on fruit, but given the gaminess of venison, this might be less of a flavour clash than actual fruit.

Unsweetened chocolate is usually used in the former, but if you want something sweeter, then you could substitute bittersweet chocolate here.

If that idea doesn't turn you on, I would stick with a mild unrefined sugar (i.e. brown sugar) or maple syrup.  The notion of chili peppers, beer, kidney beans, venison and a sweet fruit in the same stew sounds like a risky combination to me (but then again, I can't claim to have tried it).  Personally, I'd have to recommend a subtler sweetener.