Yea maybe something to looking into (ssd's) but like I said something you don't have to have.
out of 10 how hard is it hmm I would say a 7. It is pretty easy but its also easy to make silly mistakes along the way. Just take it slow make sure things are connected right that you use standoffs for the motherboard. That if you are using a aftermarket cpu cooler to make sure there is thermal grease (someone on the forums forgot it and had a cpu hit 90+ degrees). I really like the instructional videos that newegg puts out here in the states you may want to take a look if you haven't
http://www.youtube.com/watch?v=d_56kyib-Ls&feature=relmfu
And cable management ease is really based on the case you end up with. I'm unfamiliar with the case you have chosen. I typically go for Cooler Master cases the HAF series in particular is good because it is built with air flow in mind.