I fly 3-4 short hauls a month and 8-10 long hauls a year. I use an Ipod and Ety4p. Carried accessories include a DIY battery for the Ipod, the ipod-->usb connector, an extra pair of foamies, Ety's airplane plug adaptor, disposal alcohol wipes, and a small felt bag that everything is thrown into.
My priorities are similiar, except putting comfort above isolation and sound quality. If you're going to wear headphones for a 12 hour flight, comfort will end up being your #1 priority.
For comfort, foamies for me feel more comfortable than tri-flanges. After a few hours, the plasticly tri-flanges feel stuck to my ear canals and besides not feeling well, I feel like I have to very careful removing them. Foamies work well but are a hassel to put in and take out. Leave one out before takeoff so the stewardess don't bother you. Brand wise, foamies feel about the same to me. The Shures feel a little softer and the Ety's rougher. But once they're in, they feel the same to me.
For ultimate comfort, get custom ear plugs. Its possible to get custom plugs for Ety's and other IEMs. They fit well, seal well, and pop in and out easily. I've had mine for just a little over a year and won't switch back.
Isolation with the foamies from any brand is about similiar if you get a good fit. Triflange isloation varies from brand to brand and really depends on your ears. Foamies isolate slightly more.
Sound quality...truthfully, towards the end of a long tiring trip, who cares. E2s worked just as well for me as Ety4s. Sound quality from portables leave a lot to be desired too.
Other notes....go ampless. Too many little cases, extra batteries, and wires just makes travel difficult. Though I haven't had anything confiscated yet, there are stories of portable amps not making it through security.
Shorten the wires and get something to wrap the wires around. Untangling stuff is a pain and all the extra wires is just waiting to snag on something. Snip and resolder. You can always get an extension cord.
Ipod batteries suck. Fortunatly you can make your own USB battery pack for a few cents.
Carry little disposal packets of alchol wipes. It a dirty world out there. Rolling the foamies or just handling custom foamies is a sure way to get that dirt and germs in your ears. Wipe your hands and the plugs off once in a while. There's nothing worse than an ear infection and heavy airplane travel.