Hi TLS,
Any suggestions you have for the ad would be appreciated. As far as "no driver specified, except 18" long throw". Sorry, but you must have looked at a different ad. My ad specifies the exact models of the drivers down to the ohm immediately after the description and I never mentioned long throw.
Your suggestion that every driver needs a specific cabinet, have no clue what you mean. Enclosure, application, room, amplifier... all important and there is never the perfect driver.
In the case of 18" drivers, the B&C driver is probably second only to B&Cs 18IPAL driver for these cabinets in a home theater application. The FaitalPro is as good as the best drivers recommended on GSG site and better than many commonly used drivers like the Dayton Audio UM18 (which are great for my sealed boxes). All of the GSG recommended drivers are are cheaper drivers than either of these. Granted, the added cost of Neodymium in a marty is really unnecessary. Marty subs are impossibly heavy. Ten pounds either way will only make a difference when you are dropping them in. Ohms depends on a particular amp, wiring, bridging...
You can check
http://www.loudspeakerdatabase.com/ and import various drivers into your sub design program. I think you will find the two drivers used are not only adequate, but superior to most others commonly used.