AmonRaa, you are doing an amazing work, a single fan yet powerful system. That's exactly what I was going to do (until I met HR02 compatibility issue), though I will stick to use at least 800rpm rear fan

I suggest you organize your configuration & temperature test well, together with some pictures, it will be a very valuable thread for Solo users.
Regarding cut off the PSU bar, personally I quite dislike modding due to terrible mod skills, also because the modded configuration is not easy for the others to follow up (I assume half guys are lazy man just like me). Now I'm still using the old HR01 PLUS, together with an additional 600rpm CPU fan.
However, I was suffering the air resonance problem, i.e. the system noise is much larger after the side panel closed, comparing with opening the side panel. This is discussed in another mail thread (
http://www.silentpcreview.com/forums/viewtopic.php?t=60171), could you help check whether the similar thing exists in your system? If so, how would you solve it? Thanks a lot!