How much sugar should I add for my 1 gallon batch

I just bought some safale s-04 dry ale yeast and would like to do a small 1 gallon batch of cider.. I'm a noob and I'm used to using champagne yeast so I'm not sure how much sugar to use.. It's a 1 gallon batch using store bought cider with 1 can of blueberry concentrate. I want to ferment it to enough but still be able to bottle carb. to sparkling..
How much sugar do you recomend i use.... in addition to the cider and can of concentrate?
How strong will I be able to make it and still carb?

also...Before i bottle i plan to add an ounce of rasberry extract and a little lactose and also table sugar for carbing.. I feel like i usually use 1/4 cup of sugar per gallon.. does that sound good?

I'm sure someone can give you a better answer here, but for my first batch (somewhat successful), I followed this site... http://makinghardcider.com/making.html

add 1 lb of table sugar, that should get you to about 14%. if you want to go small, as you say, 10 oz should get you to about 9%.