I use the Resmed S-8 Elite with humidifier. The carrying case is very similar to a laptop case, very easy to travel with. The website Capprexy1947 mentioned ( www.cpap.com ) is a great website with just about every cpap machine and mask on the market today.
A few months ago they started requiring that people taking a cpap machine through security remove the motorized part and put it into a bin like you have to do with laptops. Some times they will still take it for additional screening (swabbing it) and some times they don't, it always varies. Remember, you always have the right to request that the screener handling it to put on fresh gloves. I travel weekly with mine and have never had any problems with it.
Good luck!