I used "Kona Honu Divers" back in November.  I would *not* use them
again, as they were too much of a tourist cattle car operation for my
liking.  I found it very frustrating to show up at the appointed
meeting time and then be expected to stand around on the dock to watch
them set up rental gear for 30 minutes before they were finally ready
for customer boarding.

Looking at their website, they run a sixpack.  Their night manta dive
is also cheaper than what Kona Honu charges, so knowing nothing else,
they would already be on my short list.

I'd also look them up in the "Big Island Revealed" guidebook; here's
the publisher's website:

http://www.wizardpub.com/bigisland/bigsample.html

I have a copy of it at home; if I get a chance I'll post what they
say.  FYI, in their online update section, they report that "Kona
Coast" under SCUBA (page 227) was bought by Jack's Diving Locker.
IIRC, Jack's gets pretty good reviews .. I'd probably look into them
some too.

-hh