I started with traktor and the learning curve isn’t that bad. especially if you have previous experience dj’ing already. My preference is with them because it’s very easy to set up and have an uninterrupted workflow.
Basically:
Traktor is a 4 deck beast of a program that has about 30 effects built in, the layout is expansive, but not too cluttered so you can’t see what you are doing at any given time. It is great for building sets that are ableton-esque (meaning the 4 decks are good to all run at the same time with various pieces or loops), and the scratch version is being championed by many many many great turntablists already.
Serato on the other hand, is a two deck workhorse. Effects are only available via external hardware addition (i’m led to believe, anyone can correct me btw), but it is able to connect video to music so you can essentially scratch and blend live video while you are playing as well. The Layout is intuitive as well, one thing it has over traktor (up for debate) is that the visual representation of the waveforms are side by side, making it a lot easier to visually beatmatch as well. It also has the ability to “bridge” with ableton, meaning it essentially does the same thing as traktor in terms of building sample and loop based sets.
There are also mixmeister, virtual dj, and a host of other dj programs, but the two i went in depth with are industry standard.
As for the mixer, if you have experience, then you would probably have a preference as to what you would like, be it 4 channel, 2 channel, allen & heath, pioneer, behringer, vestax, or etc… but i would like to point out that midi capability in a mixer can go a long way with a digital set up.
-If you are on a budget, the behringer ddm-4000 is a great starting piece, it is midi, 4 channel, and costs a little over $500 (can) but some people have expressed concern over the stability of the faders and knobs.
-Currently the “industry standard” in clubs is the pioneer DJM-800, and for good reason, it is a solid beast of a mixer, that is also 4 channels, but i don’t believe it is midi. I can cost upwards of $2000 but will be lowering in price now that pioneer is coming out with the Pioneer nexus.
As for external audio interface, nothing has been beating the Native Instruments’ line of cards, be it audio 2, upwards to audio 10 interface, they all provide very stable and wonderful sounding music.
As for the keyboard, I don’t really have anything to say about it, i’ve been using the one on my laptop with no problem, but you may want to think about getting a laptop stand. The crane stands that they sell in the store on this website is pretty much the best you can find, it is sturdy and robust, and can fit up to a 19" without having any issues.
Something that you might want to consider is picking up some midi controllers, be it the vci-100 or a traktor kontrol x1 (maybe two of them), a traktor kontrol s4, or simply grabbing a hold of a couple of turntables.
Hope that helps!