best on-line resource to purchase multiple white pines ?

I need a fast-growing evergreen screen and I need advice about where to purchase white pine evergreens. Seedlings or transplants? What is a reasonable size to purchase that will survive?
Should I plant them this fall or wait til spring?

Go for smaller plants, 20-30cm tall, unless you have deer problems. Try forestry suppliers.

Resin

2-2 white pines are available from pennsylvania nurseries , musser forest
pike's peak nursery and carino . 2-2 transplants did better for me than
2-0 or 3-0 white pines , i planted using the water gel , or you can just
water the trees the first few years

Your county/state extension service may also offer pines for sale in bulk. Usually in the spring though, which is the better time to plant pines.

I do have deer problems.
what are 2-0 and 2-2 etc. plants?
also---water gel
You can see that I am a novice on white pines.!!

First figure is years in a seedbed, and second is years after transplanting. So 2+0 means a seedling 2 years old, not transplanted. 2+2 means a plant 4 years old, spending 2 years in a seedbed, then transplanted into a separate bed and grown on there for 2 more years.

With deer problems, you'll need either to get larger plants you can protect individually, or fence the whole line off. When deer come, white pines = candy.

Resin

I use a water gel called TerraSorb. I get it from Gardner's Supply. They are water absorbing crystals made of non-toxic potassium-based polymers that swell from the size of rice to 200 times it's size when water is added. They help keep your plants hydrated so you don't have to water as much. You have to be careful when using the stuff. I always put my crystals in a bucket of water and let them swell first. I never add them dry. A tablespoon of dry crystals turn into many cups full of gel. If you put too many dry crystals in your plant hole, when you water they swell and will push your plants out of the ground. They are very useful especially in container plantings.

try these guys http://www.jfnew.com/ShoppingCart.asp?type=2&CategoryID=2

I bought white pines through Musser Forest--the prices were reasonable. But the deer ate them up! I have maybe 4 surviving of the trees I bought and all have been heavily browsed.

Arborgen has pines (but not white pines) for a very reasonable price--here is there website:http://www.arborgen.com/forest/

I bought my seedlings there; you get a lot of healthy seedlings for a reasonable price, and they are pre loaded with fertilizer and moisture retention crystals. Here is a pic from an old thread I posted:
http://davesgarden.com/community/forums/fp.php?pid=4716316

They have hardwoods too.

Try the PA Dept of Forestry. I know here in KY you can buy bundles of 25,50 or 100 seedlings from the Forestry Service.