"Whatever you do, DO NOT PICK SERATO ON THE BASE THAT OTHER PEOPLE USE IT. This also applies to Traktor too."
This also applies to Tech 12's, IMHO.
I run 4 different mobile rigs, all with Serato. 2 with twin Pioneer CDJ1000/mk3s and 2 with pairs of Stanton STR8.150s...which, I prefer greatly to Tech 12s (I also have several Technic decks that we don't use any longer).
I also have Traktor and DJ1800. Serato is a great choice, if simply for the wide-spread support. Traktor (or any NI program for that matter) is also well supported, just not used as often in my neck of the woods.
Don't forget your coffin or separate cases for protection. Also, someone else mentioned it as well...a decent to high quality mixer is a good (great) idea. You can go cheap, but you'll end up replacing it.
Are you going with TTs for the look or because that's what you're used to for scratching? If just for the look, I would back off and buy CDJs. Turntables, again, as others have mentioned....need a decent stylus/cartridge, much more care, and a stable foundation. Again, Just my humble opinion.
We also have a couple of CMX/DJM 3000 rigs which are battle proven and bulletproof. They are often the requested rigs of a couple of my employees as they are lighter, pre-racked, and solid performing setups. Unfortunately, not the best for scratching...ymmv
J