VA is a DL redemption partner, separate from skyteam. Same is the case for Malaysian, Hawaiian, Alaska, Air Tahiti Nui, etc.
You can check VA availability online by getting a velocity rewards account.
Korean Air availabilty is hit or miss with patience required while searching.
One trick is that while KE may only release 1 J (at a time for ex-US flights) it will re-populate the availability bucket once redeemed, thus if you ask for the itineraries to be built separately you can get multiple seats of the same flight. I had a wonderful phone agent do this for me and it worked great.
I'm leaving mid-Jan 2012 for 4 weeks.