I recommend you add a few landbased operators into the mix. I have dived with Uepi, Dive Munda and Dive Gizo.
I can highly recommend Dive Munda and Uepi.
Dive Munda are very photographer friendly and flexible. Jen and Graeme - the owners - are photographers themselves and have trained the dive masters on how to handle kit. While living in the Solomons, half way between Uepi and Munda on Tetepare, we did more than 50 dives with Dive Munda over 18 months and were always able to dive at our own pace.
The diving off Munda is spectacular and hugely varied. We enjoyed everything from WWII planes and wrecks, to caves, walls and muck. On the big critter front, we encountered hammerheads, silkies, silvertips, oceanic whitetips and the usual whalers, reef sharks, turtles, eagle rays and mobulas regularly at many sites. We also really enjoyed the spectacular, healthy hard and soft coral cover and Graeme's 'mighty fish army' of trevally, couta or snapper that he managed to summon - arms outstretched - with remarkable consistency. For tiny stuff there are pygmy's, pink hairy squat lobsters, nudis, cuttles and more little crusties than you'll ever need. There are great wide angle and macro opportunities. On boat trips to and from sites we saw spinner and bottlenose dolphins, dugongs, pilot whales, sailfish (which unfortunately disappeared before we could get in the water) and exquisite island scenery.
I've seen plenty of photos made by divers on the Bilikiki and I never saw anything that made me think I was missing out focusing my diving around the Roviana Lagoon off Munda. On the contrary, I'd probably choose Munda given the option. Then again, I haven't actually been on the Bilikiki, so I might be biased. I just checked Bilikiki prices and the dives/accom rates are around double that of Dive Munda.
Provided divers were competent, Jen and Graeme seemed more than happy to allow them to dive at their own pace. On many occasions our dives were pushing 1.5 hours and we spent as long as we needed with productive photographic subjects. Another thing to note is they now have Nitrox which is great extending dives at moderate depths.
Accommodation at Agnes Lodge (next to dive Munda) is pleasant and relaxed but perhaps not quite the same standard (or price) as Uepi. It is clean and comfortable. There were some new rooms going up before we left last year, so accommodation might have further improved. Food at Agnes Lodge is good, but again probably eclipsed by Uepi which is possibly the best place to eat in the country.
Dive Munda will also pick up divers from Zipolo Habu resort on Lola island which has beautiful leaf house and villa accommodation and excellent food. It is a beautiful place to stay. This is a really good option.
We've done a dozen or so dives with Uepi. Our experience was somewhat different from Brendan's, although that may have been a difference in dive masters? We dived with Jill and Grant who were fantastic. Again we were able to spend as much time as we needed with subjects and dive at our own pace. I'd be pretty confident that you [brendan] might have had some luck approaching either Jill or Grant and requesting some macro time in the lagoon. Obviously this advice is a bit late now, but hopefully it might help others. They really run a great show at Uepi and I'd certainly include them in the mix.
We also did half a dozen dives with Dive Gizo. The Toa Maru wreck is spectacular, but we found the coral health on several sites was diminished, some of the dive masters lacked a degree of professionalism and the dive sites were generally less interesting than those around Munda. Obviously everyone's taste is different, but Gizo was definitely our least favourite.
So my suggestion is, if you have the time, do a stint on the Bilikiki and then drop in on Munda for a land-based sojourn staying at Zipolo Habu. It is just one quick flight from Honiara.
Let us know how you go.