Upgrade Krell KSA 250 to what?

Here's the situation:

My 30 year old Krell KSA 250 (upgraded/hot rodded at the factory 20 yrs ago) is showing signs of age.  I'm having trouble turning it on/off and I'm afraid it needs service.  While I've enjoyed it tremendously I'm naturally wondering about replacement in lieu of spending significant sums on updating it.  Furthermore, not sure if the Krell factory is willing or capable of servicing an amp of this vintage.

So I've been toying with replacing it with a new or nearly new piece.  Options I'm considering are Pass labs (possibly X250.8 or 350.8), ARC Ref 75 SE or possibly a Ref 150 SE (used), or similar.  D'Agostino dealer is nearby as well along with a VAC dealer but both those brands are too rich ($$$$) for my blood.  Trying to stay below $10K, preferably less than $8K.

The system for this change is composed mostly of older gear, as follows:

Wilson Watt/Puppy 7

Sota Star III/ SME V/ Benz Ruby Z analog front end

Oppo 105 digital player

ARC Ref 2 Mk II line stage

ARC PH3 SE phono

Straightwire/ Cogelco/ Purist Audio cables

Thanks in advance for the input!