I've got a pair of some Andrew Jones designed Pioneers which I bought from Best Buy for a song after they got rave reviews. In my opinion for my Home Office they are great.
As for the ELAC B6s, they too have rave reviews but you should be looking /listening for Home Theater Speaker systems rather than a pair of this, then adding a center channel, etc., as eventually you'll buy them all and have to live with them in your system.
There is a review of the Debut system on site here:
Code:
http://www.audioholics.com/tower-speaker-reviews/elac-debut-loudspeaker-system
But I can save you a read and cut to the chase.
"If you’ve been cash-strapped and wanted to get great sound at home, then put pen to paper and drop Andrew Jones a big thank you note. The ELAC Debut is a darn great speaker line. What a superb example of mixing science and art to produce a true masterpiece. Certainly, at this price point, the Debut speakers have their flaws, but I never did find a real Achilles heel. Those flaws never undermined the many strengths of the setup. That’s a real testament.
So that there’s no doubt, I’ll say it plainly: The ELAC debut is an audiophile and home theater bargain. While the ELAC Debut won't dethrone $5k/pair or even $2k/pair competently designed speakers, it will give speakers at least twice or even three times their price a serious run for their money--knocking a few off their perch along the way. Highly recommended!"
However these come with small tower speakers which may need a WAF adjustment. Some ladies like them rather than book shelf types, and you can adjust their location in a pinch. Place them against the wall out of the way, and pull out them to the correct location for "serious" listening. However, I have read articles with B6s as the Fronts and B5s for the surrounds which are also pretty impressive.
I'd recommend you look at a different Sub, as the gents here have identified a couple good ways to go. You may want to look at a wireless sub, and do the subwoofer crawl to find the right placement for it. Trying to guess a good spot now is fruitless. Wireless Subs (other than you still have to plug it into the power at the wall) often gains you a good WAF you can trade to get the something else => Like small towers.

I cannot harp enough on how speaker placement, seating, and the topography in your listening area will affect the sound.
Was I correct earlier when I said you can still rough in the speaker cables?