Overall I'd stay away from any Spanish Lavenders, they are not cold hardy enough.
How cold are your winters? If you're above zone 5, the standard English variety Lavendula augustifolia (sold under names like "Sachet" or "Royal Velvet" will do well and serve the purpose of oils for soaps and shampoos. If you're above zone 6 and you can find the variety Lavendula x intermedia/lavadin ("Gross", "Hidcote Giant", "Provence") would be your best bet. These produce a lot more oil than other varieties and are just beautiful, keeping in mind they need more room. Of course, they are a hybrid and will not produce true to seed, but you can divide the clumps in year 2 or 3.
You can also cover your lavender in hay, burlap, or other "overwintering" techniques to keep them safe.
Good luck!
Carlos