[LAU] Microphone Pre-amp with an S/PDIF output?

The time has come for myself to acquire a microphone pre-amp. I do not require more than two channels and in fact, will probably do mostly mono recordings. My current audio card is a an M-Audio 2496, which has RCA and S/PDIF inputs. Due to the phasing out of PCI slots, it seems that USB interfaces are what most people are choosing to purchase these days. However, I was thinking about getting a microphone pre-amp with an s/pdif output.  My thinking is:  (1) One will always be able to buy PCIe cards in the  future with S/PDIF  (2) I don't have to worry about drivers.  Just plug  this pre-amp into the s/pdif input. However, it seems that the options for such a pre-amp are limited.  I found the following items:    (1) ART DPS-II Digital/Tube $265    The price does not seem unreasonable for a quality pre-amp.    This thing does have a lot of knobs though, and therefore    probably has more functionality than I know what to do with.    (2) Samson C-Valve Tube Microphone Preamp $99    This item is discontinued but still available on amazon.    This item did not review well on this list, but ...    it is inexpensive. Is anyone aware of other options? So what do people think of this plan?  Or do people recommend that I just go ahead and get a USB interface? Thank you for your help.