I have spent the last year recording extensively at 96khz. There are only three real features of 96khz recording that I notice:

1) Stereo  imaging seems slightly better
2) Mixing it is much easier, much more headroom, I haven't used a compressor in ages
3) Recording low volume (environmental) sounds sounds much better.

That said, recently I moved back to recording at 44.1.

1) What you hear is what you get - if you are primarily targeting CD - many an export from 96khz to 44.1 has gone south for me.
2) Much less disk space used
3) Lots more tracks feasible
4) Most plugins were designed and tested at 44.1 and 48khz and sound best at those rates

So, given that my mics aren't capable of exceeding the headroom afforded by 96khz, I don't see any good reasons to go to 192khz, and I plan to only rarely and in special situations, move up to 96khz in future recordings from 44.1 or 88.2.
 

So... when I decided to get up to 16 tracks on my RME-multiface I just added an 8 pre Digimax FS and connected it's ADAT output to it. The pres are very quiet and sound pretty darn good. Now I can do 12 tracks at 96khz or 16 at <=48 - but it won't do any higher than 96khz.

So the original thought of fireface + digimax FS might be an option so long as you stayed below 96khz.

Hope this helps.