Hi B.,
You have some great advice here, although I'd stay away from the drugging recommendations---not only because of the obvious reasons, but also because I have read many posts that say that Benadryl can have the opposite effect and make a kiddo hyper, versus quiet...yikes! Can you imagine?! ;-)
Anyway, I traveled with my 6-month old and it was a piece of cake. We used our stroller/car seat combo until we turned it over at the door of the airplane. We also packed our baby bjorn carrier just in case, but never used it the whole trip! I think it really depends on whether your little guy is still in his infant carrier/car seat/stroller combo (ours grew out of his first car seat at 8 months due to his height). If he's not in his car seat anymore, then the big stroller might be a bit much...a small umbrella stoller and a baby bjorn or sling-type carrier might be better and take up less space.
I then breastfed---in a window seat (less of a view from other seats), under a shawl-type cover---during the ascent and descent and he mostly slept for the rest of the trip. He had a full belly and was lulled by the loud engine sounds (sit toward the back of the plane by the engines). It probably also helped that he wasn't walking yet, nor did he have any desire to be very mobile at 6 months old...is your son walking early?
It was soooo easy at that young of an age (now, when we traveled with him again at 17 months, that was a different story...what a nightmare!!! But toddlers are a whole other can of worms...extremely independent and mobile, so we had a tough time. Lesson learned, which you can use later: when your baby reaches toddler stage and his favorite word when he is on your lap is "down" (repeated 2,000 times in a row), don't do the lap child thing...buy him a seat and strap him in his carseat!!)
So, back to babies: in short my advice is to time the trip during a feeding, then napping period of the day, reserve a window seat at the back of the plane, feed him on the ascent and descent, and pack only a few of his favorite toys/snacks (although remember you want him to bf or bottle again at the end of the flight, so don't fill him up with snacks), as well as an extra couple of diapers and a change of clothes. Check all of your other bags...you don't need the hassle!
That's all I can think of and I hope it helps!
D.