Seedless table grapes

I live in northern Idaho, zone 7A.  I am interested in planting some table grapes this fall.  Please provide some ideas on good varieties as well as where to purchase the root stock.  

Thanks!

Here's the grape varieties I planted this year. I have no idea if they are any good or not, as they won't fruit for another year, but I have their cold-hardiness listed.

Plant species	Supplier	Fruiting season	Hardiness
Somerset Seedless (Red, table)	Starkbros	August	Hardy -30°F
Somerset Seedless (Red, table)	Starkbros	August	Hardy -30°F
Lakemont Seedless (Green, table)	Starkbros	Late August	Hardy -15°F
Lakemont Seedless (Green, table)	Starkbros	Late August	Hardy -15°F
Saint Theresa Seedless (Purple, table)	Starkbros	Early September	Hardy -30°F
T210A Crimson Seedless (Red, table)	eBay	October	Not Hardy, only 0°F (USDA 7)
Golden Muscat (Green, wine or table, seeded)	Starkbros	Early September	Hardy -15°F

Steve Thorn showed me this site that lists the hardiness of many species.

I'm in USDA zone 6A, which means I get down to -10°F. You, in USDA 7A get down to 0°F.
(except in really abnormal extreme situations, where we might both go down an additional 5-10°F of our normal years).

I bought almost all of mine from Starkbros for about $12.50 each, waiting for their frequent sales. Their normal prices are $15-$20 each, unless buying multiples of the same species.

I planted hundreds of seedless table grapes 20 yrs ago and they are still growing like crazy but I no longer have ready access to the property. ive been hoping I could go back and trellis them, time will tell

I've tried a lot of varieties of table grapes. By far the most flavorful are those with seeds. Sure I gotta make the choice between chewing up the seeds or spitting them out, and seeded table grapes don't go over well at farmer's market, but for me and my friends, eating fresh fruit in the garden, I'd go for seeded grapes every time.

For me the big advantage of seedless grapes would be that I could dry them for raisins, which I would probably use more than fresh grapes.  My main grapes are seeded and I now wish I had a seedless variety.  No more room in the polytunnel though.