On the 747 it used to be 1 div aileron trim for 5 kt crosswind component. Not sure for the 737 as it's not as clear on the control boss. I would suggest going with 'a little' (like 10 degrees) for a low crosswind, more (about 15 degrees) for a medium large crosswind, and see how that works. I don't think spoiler drag is a big problem on take-off- all the speedbrakes aren't exactly powerful even at 250 kts on a 737. A couple just floating up gently below 150 kts isn't really going to have any effect dragwise at all.