Neither the B-G or Hi-Vi is a ribbon. They both are planar magnetic types. Both might require a steeper 2nd order crossover. I know that Hi-Vi makes a larger planar tweeter that can be crossed over fairly low. You might get by with a simple crossover. I haven't played with the B-G tweeter, but they are highly regarded. In any case, the available, or reasonably priced units, are a bit low in efficiency. I'd go with the dome. I found a couple of air motion transformer types that could work, but that would put you in 3 or 4 Pi pricing.