I am with you on iTunes. Hateful piece of software. You can either do it the Apple way or not at all. Ever tried copying a few playlists from one device (iPhone) to another (iPad)? Especially if one of those devices is not yours? Drama.
But, this thread is not about iTunes bashing.
Depending on what you want your software to do (it sounds like you need it to be just library management really) and what brand CDJ’s you are gonna end up with, RekordBox (Pioneer) and Engine (Denon) would be valuable options.
Which brings us to the subject at hand, what CDJs to buy (and what mixer? … assuming you want something to hook the CDJ’s up to).
Obviously there is a big choice out there. If you plan on ever playing on rented equipment or in clubs/venues with fixed installations, then (unfortunately according to some) your best bet would be Pioneer.
When you say Pioneer, you could either go low budget and get the Gemini CDJ 700s which are more or less copies of the high end Pioneer models (and oddly enough have been taken out of a lot of shops here recently, copyright infringement anyone?). The only cost a fraction of “real” CDJs and give you the almost exact same workflow.
Then there is Pioneer itself. Don’t go the 350 road, they are way too basic to be any good, unless you use them as controllers for Traktor or VDJ or something (although I think they are a tad on the pricey side for that). 800s, 900s or 2000s. None of them qualify for your criterium of “cheap” though. Starting at about 850 euro here (800) up to more than 1800 euro (2000) a piece, they are pretty high price.
An alternative that I chose is the Denon SC2900 (and I got the X1600 mixer with it). Not cheap, but definitely way lower in price than the Pioneers and Denon is, for sure, a pro brand. They make great quality gear.
You could also opt for stuff like American DJ Radius 3000 or such. There are plenty of low(er) end CDJ players.
Greetinx,
C.