If you like Linn, it sounds like the Classik Movie is what you may be looking for. One box with a CD/DVD player, pre/pro and 5.1 channels of power amplification, and a tuner to boot. You should be able to find one on Audiogon in the $2500-$3000 price range. What you don't get is SACD or DVD-A, HDMI, processing for 6.1 or 7.1 surround, or upgradeability to Aktiv however. Musically, you won't be missing anything if you're running a 15 year old Pre-tek/Power-tek combo. It's as good as you'll get for a one box solution.
The next step up would be what Jim is suggesting above. A Unidisk SC and 5125 power amp would run you about $5500 on Audiogon.