(note - have not read the whole thread so might be repeating things).
I don't know, I think people make a bigger deal than it's worth. Yeah its going to be hard and sacrifice, but that's also true for parenthood in general. We have travelled transatlantic with a ADHD child and another that is also quite active. Done so as a couple, also me alone, also my wife alone. No big deal - ehm, sorry, yes, it's a big deal but for us well worth it and doable - take a positive attitude! We do a long haul, to South America, with connections at either end. Now that we have 3 we have only done short haul flights, long haul now we will do together, alone impossible until older is quite older
Don't have much time now for a full answer (putting children to bed) but - keep them entertained, new toys, things they like, bring an ipad / portable dvd if they like that, and also - might be hard to swallow to some to do this - drug them (slightly, carefully of course) to help them sleep. This is important, if not it will be hell / very difficult for them to sleep. By drug them I do not mean sleeping pills, but something you would give them normally that causes some drowsiness.
If you can afford as well UPS most of your luggage so you don't need to handle more than a suitcase on your own + the kids in your transfers through customs. There are companies dedicated to this and prices are not as steep as a real UPS shipping. People will help as well, if you approach an airline person and ask, they will carry your child or your luggage (I've done many times). Try to keep your packing to something you can move at once yourself - kid on a backpack or dual stroller, large bag for toiletries, another for toys, stroller for other kid, but not much more....
Calculate A LOT of time for everything - security, transfers, etc. More than double what you need. DONT WORRY ABOUT OTHER PEOPLE behind you being impatient, don't hurry more than needed, don't loose control of the situation. Security is tough for us but I literally ask any lady at the security point to hold my baby and they will (or they outright offer to do so). Try to take as direct as possible flights, but if you have to connect, never do on less than 2 hours (doable but normally avoidable and can be risky). A long connection is normally better than a short one - most major airports now have playgrounds and the time to run and relax helps them very much (I usually plan around my transcontinental about 5 hours stop on each location).
Consider upgrade to business class if you have miles (but this not often the case for most - and to be honest, I've done it only once and it is not that much of a difference... will not do it again - you are not going to enjoy the wine and nice dinner!). If not, you MUST get the bulkhead seats ahead of time (most airlines even reserve this until boarding for families) and ask for a the small bed - I think it's called basinet - (up to about 1.5 year old will fit well) they can put in the bulkhead. But ask for this ahead of time, insist at check in they check it is on board, ask upon boarding, etc - it makes one hell of a difference to be able to put them to sleep besides yourself. Also check for airlines with in-seat enternainment that you can choose your own channels or play games. They will have kids programs so this will keep them busy a few hours and is a blessing.
Also many airlines given your situation will 'help', take extra considerations, for example, if the flight is not full ASK, smile, also beg, that they reserve the seat next to you so you have a full row or some extra space (they can reserve the space in their system so its blocked until absolutely necessary, do it all the time for us frequent travelers).
Sure, it will be tiring and long, but doable. They will keep you busy (as in the house!) for sure, but again, it's doable, just a sacrifice. Plan well, really keep new toys for 'surprise' every couple of hours.
As all good things takes effort. A hard part we didnt expect was the time zone change - this was harder for us. When we got to America they where in European time, so sleeping in the day (when we where busy with family and friends), and at night, eyes wide open wanting to play around. This took a few days more of work.
Very often people on the plane are very sympathetic and will help you far more than you expect. Stewardesses as well. Now I just look for people that look in the right attitude/age bracket and ask them to spend some time with them to go for the bathroom. You can go to the open spaces in the front, exits, rear and set up a small play area. Ask the steward (they will do this) to keep your meal for after you are done with the children, to bring it later.
Anyway, good luck, go do it!!, but plan well, read, reasearch, but do it.
You must check flyertalk.com, search there, you'll find EXCELLENT threads there on tricks and tips, do that, it helped us as well. Food is also important to plan ahead well - lots of tips on this on that forum. Planes have microwaves and always bottled water, but other essentials (as diapers) you must take extra care to take far above what you normally need (think, stomach problems!).
Anyway, good luck - now my wife is angry I did not help put the kids to bed
heading up to tuck them in. Bye!
Juan Miguel Venturello