I had Dynaudio Contour 1.1's with a Nap250 and loved them. The sales manager for Dynaudio used to run Naim amps.
With your system, you don't need a preamp if you are using SBT/MDAC only.
Therefore, my advice if you want to keep the Contours is to buy a power amp. Where do you live? I'm happy to demonstrate my spare which is a Avondale/Nap250 clone. I'm near Horsham. Otherwise maybe Dynavector which is potentially the next step up and will give you a variety of speaker choices. Also look at the heftier Meridian power amps and maybe Exposure.
I'd definately say borrow one if you can, then second hand also won't loose you money and will give you far more bang for buck.
Cheers
Jez