I would ask first what is your budget? Do you want to go full monty with a pair CDJ 2000s and a mixer or one of the latest hardware controllers using the likes of Serato, Traktor or Abelton.
I have used 3 types with varying outcomes...started with a Numark HDMix http://www.numark.com/product/print/hdmix
(which is about 6 or 7 years old) which is a portable expandable DJ system, with no software involved (all down to your mixing ability, this was the closest I got having never used turntables and told by a friend to not get hung up mixing the old way, nonetheless a very good skill to have, however nowadays its down to more than being able to mix.
A year or so after I bought an APC40 and DJ'd with Abelton, which is a steep learning curve as the APC40 is really for producing first and foremost...however I did enjoy using it and found Abelton reasonable once I had got to grips with it even though its a beast!
Right now and today I use a DDJ-SX http://www.pioneerdj.com/en/product/controller/ddj-sx/black/overview/
with SeratoDJ and have to say I love it, way more choice of functionality than either of my previous 2 pieces of hardware. SeratoDJ works very nice with the Pioneer hardware with upto date software and a reasonable amount of plugins, some are missing in traktor for the ddj-sx as they provide and an official tsi for the ddj-sx. They're other models (smaller and bigger DDJ-SZ) so it depends on your budget...however lots of other manufacturers who work with Serato.
Having seen the DDJ-SX with Serato and Traktor (a friend uses Traktor on his) I personally prefer Serato DJ as I find the layout easier to ...maybe best to try it out on whatever H/W you prefer and go from there!