Hybrid - Tube / SS amp capable of sub 1 Ohm loads?

yep. or try a big pass

Another ultimatively stable ss: Tidal Impact
http://tidal-audio.de/english/startprodukteverstaerker1.htm

I amusing Wyred4Sound class D amps on my Maggies. Vheck out the SX1000s. Great price, great sound and they don't drain your power bills

Spectron Audio claims that Musician III SE is stable up to 0.1 Ohm Load - with headroom of 3500 watts over 500 msec.
This amp is neighter solid state nor its tube - its class D and for its sound description look at their web site/review page and search Internet, including Audiogon discussion forum.

Don Shaulis, reviewer from Stereo Times (who bought his sample amplifier) and has difficult to drive Apogee Diva wrote:

" I have never heard Moussorgsky: Night on Bald Mountain/Pictures at an Exhibition [Telarc B000003CSH] before. Oh, I have owned the CD for years but I never really “heard it” before. The Spectron presented the softer passages with such inner detail they became seductive but the real surprise came in the crescendos. The peaks reached were a revelation. It wasn’t that the Spectron could play loud, it was that I wanted the music louder. For the first time the crescendos were reproduced with full fury but no smearing or harsh edge that demanded the volume be reduced. Now, after many years, I finally “get” this fine recording..."

Good Luck with your search.

Don't flame me here. But you might consider a pro audio amplifier. The switch mode (Class D) pro amplifiers can deliver boatloads of current and are designed to work reliably into low Z loads. They have come a very long way in the past five or so years and some of the better designed units some very similar to the switch mode audiophile amps....seriously. Downside is that many (most?) are fan-cooled, so this may be an issue.