Audioguy, can I just chime in here? Roger and Sanjay are giving great advice but you still seem a little unsure about DSX/Wides (forgive me if I am wrong). What both R & S are saying is that if you have a proper pair of side surrounds and a proper pair of rear surrounds, and the side surrounds are moved somewhat *forwards* from the usual 90 degree position, then you will 'fill in' the gap between the fronts and the rears nicely and this may well mean that you don't need Wides at all. As Sanjay has said, the side surrounds will phantom image to some extent to the rear of their actual position and this arrangement of the fronts, side surrounds and rear surrounds will give you a terrific overall envelopment. As Roger said, if you want a slightly wider front soundstage, move your front L & R speakers a little further apart.
I was a big fan of DSX (for height channels - I have no room for wides) but more recently I have moved away from it and now use PLIIz for my Height channels. The reason was that, in the end analysis, I disliked the way that DSX actually works and the way in which it generates the 'content'. It does things to the regular 5/7.1 soundstage that is not only moving away from the Director and Mixer's intent but which also upsets the overall soundstage. It was Roger, in fact, who made me realise this in a discussion he and I had and he told me what to listen for and how to listen. This is just my opinion of course- there are others who swear by DSX and that is fine.