Got an Adcom 5300 to power my Vandies and MA Silver 6's... Now What?

So I finally bought a cheap dedicated amp for my Vandersteen 2Cis and Monitor Audio Silver 6's...  Now What???

I have some solid power now, but now I am working on ways to play my hi-res files off of my computer and occasionally play some CDs.

I have been looking at combo DAC/Preamps such as the DACMagic Plus from Cambridge, the Teac UD-301 and Marantz's HD-DAC1.  But, is this the right way to go??

Most of the preamps under the $1,000.00 price range don't appear to be competitive options compared to the DAC/Preamp combos.  I thought about buying an Adcom GTP-450 to match the 5300, but I am not convinced that it will outperform any of the combos either.  I even looked at the XiangSheng 728A (Which looks like a real gamble with it's made in China stamp and lack of any respectable dealers and/or reviews).  The NAD 165BEE looks like a good option, but they are expensive and I would still need a DAC.

I find myself wondering if using my old Onkyo receiver or even my Sony E2000ESD as a preamp might be my best option until I have the funds for something better.