rhm

Is it worth the cost? That's gotta be your call. If you're having trouble finding a bike to fit you, you may have to go to additional expense; the only way around that is if you get lucky and find a suitable alternative.

For example, there are road bikes made for smaller riders, as suggested above, with 650C wheels. There are also good old steel MTB's that take 26" wheels, for which you can get nice skinny "road" tires if you want. Another option is a mini-velo or folding bike with 20" wheels; some of these, such as a Xootr Swift, ride like a full sized road bike. If you're not opposed to a new bike, definitely look at the Swift; it's a very versatile bike (I'd ride one myself, but it doesn't fold small enough for my needs).

As for 650 B, it's certainly a possibility; I can't speculate on whether it will be enough, though. And as observed, brake reach may be maxxed out. Still, I recently put 26" (the MTB size) wheels on a bike built for 27" wheels. I did this because I wanted to use shorter crank arms without raising the seat to an absurd height; the smaller wheels lowered the whole frame tube by about 1 1/2", which was what I wanted. But I had to use hub brakes; no rim brakes would fit. If you're willing to go the expense of hub brakes or frame modifications (studs for cantilever brakes, or mounts for disk brakes, etc) then you most definitely can fit smaller wheels.