welcome aboard, you'll find many lc4 converts here (i had two ktm singles before the sd)
changes to the '07 include radial brake calipers (from the 950 SM - but not that big a difference in stopping power IMHO), a 2 litre larger tank capacity and quite a bit of cosmetic work
if you can get it new go for it, or it might be prudent to wait for the official 07 release in october and snap up a used 05 or 06 for a good deal