This url could be helpful to you in many ways, including ordering. It is recommended that you start with plants as it is VERY hard to start lavender from seeds. Of course, you can always try if you are so inclined. But this will get you started. They ship to all 50 states.

Here is a link that might be useful: Mountain Valley Growers

There are two varieties of lavender that are readily available and that could work for you, but neither one is perfect.

Hidcote is a strain of English lavender that has deep blue-purple flowers. It's about 18 inches to two feet tall. The flowering stems are relatively short, say, 5-8 inches depending on how much of the basal foliage you cut.

Good points -- the plants make a neat hedge; the color is unsurpassed, very hardy. Not so good -- the scent is very pleasant, but not very strong; stems on the short end of the range for lavender -- ok for fresh bouquets on their own or with other short-stemmed flowers, or dried bunches, too short for lavender wands.

Grosso is a lavandin, widely grown in Provence and maybe a little less hardy than Hidcote. but it should do fine in Zone 6 (that's the zone I've grown it in for the last 8 years). It's about two feet tall but can grow to 4-5 feet wide, stems about 12 inches, some a bit longer. It's a deep, dark purple, almost blackish.

Good points -- spectacular plants in bloom, long stems good for drying or lavender wands. Not so good -- take up a lot of space; scent is strong but more musky, "deep," "dark" than classic Enlish lavender scent. Some feel this is what lavender "ought" to smell like, some don't.

The Cape Cod Lavender Farm grows both varieties. If you visit them, you could probably get an idea of what each type smells like and, this time of year, what they look like out of bloom, which is how you'll see them most of the year (though there may be a rebloom on Hidcote about now).

Here is a link that might be useful: Cape Cod Lavender Farm