Maybe this has been posted already and I missed it: IRD now makes French and Swiss threaded cups as an accessory for their cartridge-bearing bottom brackets (made by Tange-Seiki, which normally come with English cups). IRD had started to do Italian cups awhile back, but now they do every flavor. Check it out on their webstore:
http://store.interlocracing.com/italianbbcups.html

The only catch is that the BBs (like the ones offered by Velo-Orange for English + French) are all JIS taper. They come in widths from 103 to 122 mm. The more expensive QB-75 is lighter, but only because they provide that with alloy cups; I think the basic BB is the same. Funny thing: the QB-75 is available up to 127.5 mm width.

If I weren't so lazy, I'd have measured the "shell to end, right" and left on one awhile back -- can't tell you whether they're symmetrical or not. Somebody should do that, or find out the dimensions directly from IRD.

Their QB-55 bottom bracket is $28, and the non-English cups are $18/pair, so that's a good BB for $46. I have two of these in use for awhile; they're very smooth, and one has seen a lot of miles on my commuter.

Update: I splurged, because I have all three types of bikes, and bought a set of each: Italian, French and Swiss -- and guess what: they're alloy, rather than steel.