A lot of good advice above. If you can track down Coshell charcoal, it makes very little smoke when starting a chimney. Much less than KBB or Stubbs. And what smoke it does make has a sweet, mild smell.
On the other hand, lighting a charcoal barbecue seems like a very reasonable thing to do in your own back yard. Maybe the right answer is to agree with your neighbor that you will indeed use charcoal cookers, but will do the polite thing and give them a heads up to close their window. And most things are better when you have a friendly relationship with your neighbors.
And maybe hand a plate of ABTs or something over the fence every once in a while. A little food bribe can't hurt.