Krell amp upgrade question

A little background: I used to drive a full B&W Matrix home theatre system (801s2, 804s1, 805, center HTM) with a combo of Krell KAV 250a x2, and 250a/3 amps. I was very happy with the sound for both stereo and HT, and only had a ground loop issue with the front mains - thought due to long XLR runs (>15ft) and solved with "isolating" XLR plug adapters.
Fast forward to today: I just picked up a gorgeous pair of B&W N800 to replace my Matrix set. I was planning on bridging each 250a as pseudo-monoblocks but then need to decide how to run the rest of the HT. I still need to successfully drive a B&W N HTM-1 center, but the surrounds have become in-ceiling or B&W WP-1.

- acquire another KAV 250a (very difficult to source)
- bridge 2 channels of the 250a/3 for Center, and acquire another 250a/3 (also difficult to source)
- sell the 250a/3 and replace with a Krell Showcase 5/ other "newer" but less powerful Krell multi-channel amp

Of note: the 250a/3 I currently have may need service as I am noticing crackling during playback - although this may be from source material, and the ground loop is still present - although will most likely be minimally noticed in surround speakers/ can be eliminated with the isolating XLR plug adapters.

It is NOT an option to scrap everything and buy all new amps!
Appreciate thoughtful comments.
- acquire another KAV 250a (very difficult to source)"

Actually, I've seen a few of those listed recently, and for low prices. Its a pretty good amp. I used to have one. Its definitely better than the Showcase. Have you tried just 1 running stereo with your N800's? You should have enough power with just 1 amp.
I'm currently using 2 of the 3 channels of the 250a/3 to run the N800s. I'm noticing that the N800 love to suck up power and as I have the 250a that I can easily bridge, I was thinking they could happily power them. Then all I would need to do would be find a way to amp the HT side of things.

Why is the KSA 250a/3 "definitely better than the Showcase"?
If you bridge it, won't that reduce the load that you'll be able to drive by half? Unless the KAV250a is rated into 2 ohms in stereo mode, you may not be able to drive 4 ohm loads when bridged. You usually see power ratings in bridged mode for only 8 ohm loads. I don't know if that'll be a problem with your new speakers or not.
Per Krell awesome Tech support this morning: "No issue driving < 8 ohm when 250a is bridged."
"Why is the KSA 250a/3 "definitely better than the Showcase"?"

The KSA has a lot more power. I've heard the showcase strain under loads that the KSA would not. I think it sounds better, as well.
From the Krell KAV 250a manual

DRIVEN 4 Ohms 500 W
BRIDGED 8 Ohms 1,000 W
It's as I suspected, the 250a is not rated into 2 ohms and so bridged it won't be rated into 4 ohms. That's not to say this is necessarily a problem for you; just something of which to be aware.
Just because Krell doesn't print the specs for 2 ohms in the manual, doesn't mean it won't be able to handle the load. I think specs for 2 and 4 ohms are more important to people now because brands like B&W and Martin Logan are more available due to them being sold in places like Best Buy. A typical receiver just won't cut it for those types of speakers, despite their power ratings. But you do have a point about what's printed in the manual. Personally, I would like to see more specs in the manual to avoid confusion. Having owned the amp, I think it will be fine used either bridged or 2 channel.

One thing you can do that should answer some questions, is to run the amp you have bridged into just 1 of your speakers as a test. If the amp has trouble driving the one speaker bridged, you can expect the same results if you get another amp. Also, many people report that bridging a stereo amp lowers the sound quality. Of course, results will vary depending on many factors, but I think its something to keep in mind.

If you do try the single amp bridged, make sure you compare it to just 1 speaker non bridged. It makes the comparison much easier.