The internal space requirement for a CPU HSF is almost the same as the PC-Q08, and I'm personally using the Prolimatech Samuel 17 with a 25mm PWM fan. Fits just nicely. As for PSU I'm using (as suggested) an OCZ Modstream PSU, which is about the same size as the stealthstream. It works, but a tight squeeze nonetheless.
Like that Atomic Football version of the PC-Q08, gotta love those easy to remove side panels, though, is there any kind of physical support to keep the Motherboard panel closed? at least PC-TU200 was latched based.
The loss of the (optional) optical drive and front USB kinda makes it iffy for an "accessible" HTPC. What I mean by that remark is unless you intend to have a dedicated DVD/BD player, the PC-Q25 well, can't play that without an external ODD, which just takes up more space. Likewise if you or have friends/family that want to play music or bring a video, or show a picture slideshow and have it on a USB drive, it creates the minor inconvenience of having an extension cord for a back USB. Can't really beat the simplicity though.
What was it you didn't like about the PC-V354 and (related) PC-Q08, aside from ALL those dumb screws?
@Red: if you want an ODD and all the fixings in a mini-ITX case, the PC-Q08 hands down. Otherwise I agree with Steve's sentiments about the PC-Q25.