If you want to fly slow, you want maximum lift while generating minimum drag. That would be takeoff flaps. Take a look at an airliner the next time it takes off. You'll notice slats extended and a little bit of flaps. If the jet doesn't have slats, like a lot of corporate jets, RJ's, or -10 (little) DC-9's, you will see a little bit of of flap. A little flap gives lots more lift with very little additional drag. As you add flap, up to a point, you get more lift and also more drag, a desirable thing for landing. Beyond a certain point, you stop gaining additional lift and just add drag.

So to answer your question, you want takeoff flaps. I can't tell you what that is for your airplane. I would guess you are looking at 5-15 degrees of deflection, but that is just a guess.