ASUS have notoriously bad build quality and support, I wouldn't recommend it.
Alienware are good quality, but notoriously expensive (since you have ridiculous amounts of cash to drop, this isn't really a problem for you) so they might not be the best choice.
MSI have a lot of problems, they don't have a good reputation at all.
I would say the best bang-for-your-buck is probably going to be Clevo. I think you are better off getting 1 laptop, there are plenty of portable and powerful boxes available.
For example here is the Metabox W230SD (custom configuration is available, I made it soak up as much of your funds as possible):
13.3" QHD+ 3200x1800 panel
GTX 960M
i7-48910QM
16GB DDR3 1866Mhz
2x1TB 850 EVO mSATA in RAID0 (for ~1GBs access times)
Killer Wireless-N 1202 (because why not)
http://www.affordablelaptops.com.au/...-notebook.html
Remember that any gaming laptop is going to be heavier than a normal laptop, 13-14" is what I'd aim for, 15.6" is going to fuck you up, they are seriously big and seriously heavy. Alienware 13 R2 is the Dell equivalent of the W230SD, but afaik they won't do cool shit like mSATA RAIDs.
Is there an option to get a $500 laptop and pocket the 4.5k? Because a $500 laptop is going to play any competitive game anyway. I don't see the point in wasting money like this. What games do you play? Where are you from? Where are you going?