Hi there,
I use an ISP Stealth poweramp in the practice space/studio, at home as well as at gigs (if there is no board to directly plug in).
It is really small compared to a 19" rackmount unit, a plus especially because you can fit it in any backpack. It does not affect the Kempers sound at all whilst it provides up to a whoping 180 watts of power in "bridged" mode. Add to that the fact that it is considerably cheap (you can get a new one at around 350$ at Musicians Friend/Sam Ash/Thomann - or buy a used one at half that price on Ebay) and you get yourself a really good way to power up your KPA.
Since you´ve asked about a poweramp for "bedroom" use - at home I have a Mesa Boogie 1x12 loaded with a Celestion Vintage 30 - even at low volumes the sound is crispy clear and you can hear every single note.
Little tip on the side here - if you make use of a "high tech" piece of equipment like a Kemper - don´t go the cheap route when it comes to cables - I´ve noted a 100% change in both tone and clarity (to the better obviously) ever since I changed from a noname cheapo brand to Monster cables - bit on the expensive side, but my tone is worth it....
Cheers