You can grow any type you wish except for those few varieties that require a really long hard winter to mature like some of the Russian/Siberian ones. In general, softnecks will do better in the warmer climates. Hardnecks produce smaller cloves but will store longer.

But that all depends on how you plan to use it. If you want it for long term storage (hardneck) or fresh use, for canning or dehydrating, stronger more complex flavored (hardneck) or mild tasting (softneck), etc. If you want scapes in the spring for eating then you'll want hardneck varieties.

For hardnecks I like German Red or Ajo Rojo. I like Music but it doesn't do as well for me. For softnecks - Inchelium and the Californias (early and late).

Dave

You probably have the largest selection of possibilities in your zone, as it is borderline.

Dave is correct, except that softnecks are known for storing longer, and hardnecks have larger cloves. I think that may be a typo. For instance my Music and Russian Red last year have 4-6 very large cloves per bulb. Softnecks have more cloves per bulb, but many are small and difficult to use - the hardnecks don't have that tiny ring of bulbs in the middle. Softnecks are your standard grocery store fare... and that's how they were bred... to be grown as a cash crop in warmer areas. For me, hardnecks are the only way to go, even if they didn't grow best here. They have larger easier to peel cloves, are generally bigger overall, taste more complex, and have delicious scapes.

See https://njaes.rutgers.edu/pubs/fs1233/

There is a good allium forum on Gardenweb you should visit.