Jmelet, why do you want a preamp with digital inputs? Do you think in the price range of $1,000 that the DAC in the preamp is going to be better than the DAC in your CDPs? Considering all else the preamp is responsible for?
Skip the digital inputs and just look for the best preamp you can find at your price point.
As to CDPs or DAC with volume control - be careful they are few and far between that will outproduce a comparable system using a preamp. I have OWNED some great CDPs and DACs with volume control (Wadia, Esoteric, DCS stack, EMM Labs, Mark Levinson, Audio Aero, Resollution Audio) and with only one exception, each time the CDP/DAC with volume control was improved upon with the use of a preamp.
Skip the digital inputs and just look for the best preamp you can find at your price point.
As to CDPs or DAC with volume control - be careful they are few and far between that will outproduce a comparable system using a preamp. I have OWNED some great CDPs and DACs with volume control (Wadia, Esoteric, DCS stack, EMM Labs, Mark Levinson, Audio Aero, Resollution Audio) and with only one exception, each time the CDP/DAC with volume control was improved upon with the use of a preamp.