Hi from HK...
Two main schools of thought on this one...the passive type of bud which fits so snugly in your ear that it pretty much cancels out all exterior sound, or the active ones that produce "anti-noise" to get rid of most background sound. A lot of it will come down to personal perference. I don't like the bud type because they irritate my ears, but I've heard that the do cut out almost everything. Actually there is also a bud type (although not as snug) that has active NC too. I have a set of Sony NC11s which are active buds, but recently upgraded to Bose QC2s. The Bose is a proper "closed" headset, so it might be too bulky for you, although they do fold flat into a neat carry case. They cut out most of the rumble of engine noise, but if you're sitting next to a screaming toddler they won't help totally!
As far as jacks go, the only sockets I've seen on board (BA and a host of other carriers) are a standard one (either 1/8" or 1/4") or a three-pronger. Actually only two prongs are needed (the third I assume is for power). Both of my sets came with the necessary adaptors, but I've seen them for sale in airports anyway in case you want to use your ordinary set.
Do a search on the Travel Technology forum for stacks more info.
Nick