Well hopefully it isn't too late to offer my experience with travel systems. I travel a lot, and thus have a couple dedicated systems for this specific purpose. I am continually refining my current system...which is pretty darn good, if I do say so myself.
I use the cambridge soundworks model 12 as the foundation of the system. $500 retail, but you can get it on sale for $375. I've had mine for 8 years now. Takes a beating and just keeps going. It entails:
1. Bass Case, that is the subwoofer and travel case that everything fits into. Brilliant.
2. Three channel amp, which has a dedicated 120hz crossover for the sub, and 50 watts for each of the 3 channels.
3. Satellite speakers with wall mount brackets attached, and integrated speaker wire holder. (don't really use these anymore)
4. Wall plug, as well as a car lighter plug.
5. Space to carry other stuff.
So I braided my own cables out of 16awg wire, terminated with Monster flexible Pin connectors and Banana Plugs for the satellites. I carry a Jolida USB DAC to run off my laptop, and some Audioquest King Cobra RCA cables. I replace the satellites with something different every few months.
If I'm traveling by car, and gone for a while, I bring my Mirage V2 bookshelf speakers. This has proven to be the best combination to date. There is a synergy there that really works. Incredible imaging, and soundstage, with a tremendously smooth presentation. I've never had to turn it more than ¼ volume. I am going to try the Gallo Nucleus when I need everything to fit in the case. The internal spot for speakers is 4 square. I am also thinking about ordering some Canton satellites, as they will fit inside as well.
The best part of this system is that the bass is off-loaded to the subwoofer, and frees the satellites to focus on their strengths. I highly recommend it for travel. It can be checked as luggage BTW.
When I take short flights, I take the Foxl v2. Really great sound from a tiny package. Bluetooth is really handy as well. :-)
Well, I hope this helps in some way. Travel systems are tough, but sooooo important. Can't live without the tunes.
Mot
PS. Totally agree with Tobias on the A2...mine are sitting in a box collecting dust. Bass was too boomy for my taste.