Latest USB converters or music server?

I have recently purchased a Musical Fidelity KW DM25 transporter and dac. http://www.musicalfidelity.com/products/kw/kwdac_specs.html

One of the reasons for choosing this model, was that it offered a switchable facility for the dac - you can switch between the transport and a spare spdif connection.

I am keen to use computer based audio as well as CDs.

My question is: What is currently thought to provide the best sound quality given my set up?

Option 1: Laptop (I have one spare) with something like an Empiracle Audio USB off-ramp Turbo 2, fed into my DM25? This model is a few years old now.

Option 2: Power supply modded Squeezebox Duet, fed into my DM25?

Option 3: ??? Other ideas ???

I am quite happy to build something, or DIY if needed.

I am also happy not to spend too much cash.

I know that this subject is often covered, but computer gear changes so quickly these days - apologies.