Not a huge choice of SDCs. If the Schoeps are too pricey, try the Sennheiser MKH30.

Have you looked at a small ribbon such as the Beyerdynamic M130?

So can we all get together and start an email campaign to get Rode to make figure 8 capsules for the NT55? I've always noted that there was an extra space for a capsule in the NT55 case. I'd definitely pick up figure 8 capsules if offered.

I have the slots in my NT55 cases full with spare omni and cardioid capsules!

It's a nice idea, but I'm not convinced that a fig-8 capsule would work mechanically in a pencil mic like the NT55, since it is end-addressed, whereas fig-8 needs side-addressing. A longer and larger-diameter capsule narrowing to the body diameter at the screw joint would be possible, but would have a problem fitting in the foam recess in the case.

Well, I figured the height of the capsule would have to be a bit bigger than the current diameter, but I didn't realize it would have to be wider as well. Oh well, another illusion shattered.

Well, maybe it doesn't. I'm not a microphone designer, but I had always assumed that the difference in diameter between the few SDC fig-8s available and the many SDC end-addressed mics was due to the thickness of the capsule arrangement needed. However, I've just looked up the Schoeps MK8 capsule, and it's is 34mm long, but only 20mm diameter, the same diameter as the Rode NT55. So, yes, maybe it is possible, and we should be lobbying Rode, as you suggested.

I'm onboard for the figure 8 capsules!

AKG CK94. It fits on the SE300 body. I use that series as my modular mic's. I have the:
CK91 (cardioid)
CK92 (omni)
CK93 (hyper card)
and CK94 (figure of 8).

This setup works very well for me especially for quick M/S work.

Sounds great, and I think a larger diameter capsule can also use on NT55 body. Maybe it will make NT55 looks like a Flashlight, whatever, we need it.

Oh, ribbon! All ribbon mics are figure 8, I forget it.
A Small ribbon? You mean that mic has a shorter ribbon than Royer R121 or RCA 44, so it can be smaller ?

There's also a fig.8 head for Oktava MK-012, though in fact a combination of 2 cardiods, here