I come from a Audigy 2 and it has no influence on USB monica 2,
I have the windows sound coming trough the audigy 2 and the foobar sound coming trough the monica 2 usb ( using asio4all) .
The monica 2 usb comes prebuild in either a box or naked, if you order her naked you'll have to hookup some RCA cables ( 4 soldering connections ) + a power supply ( wich you can get from YEO ) , very easy and I'm sure you'll get help either here at the diy section or on the diyparadise forum.
The obbligato paper in oil (pio) capacitors are to replace the blackgate output coupling capacitors ( the small red ones) They have a smoother more 3d sound , with more warmth or fullness and bass. they are rather big tough. you can get them at http://www.diyhifisupply.com/diyhs_ob_caps.htm
not to expensive and get very good reviews from diyaudio members and shootouts. some people don't think it matters much but when I changed my trends ta-10 outputs caps to obbligato, there was an immediate improvement in musicality and presence.
Quite an easy job to do ( I'm no diy expert at all, can't read schematics) so bare with me if I used some stupid words