they need lots and lots of water in their first year ,

Cliffo's right. When did you plant them?

I'm afraid if they've turned brown all over then they're dead.

If you did everything right, then you might have redress against your supplier.

you may do better with Thuja am I right that August and April are the best times to plant evergreens-- Cliffo's right-- they need lots of water in hot weather you could even spray overhead morning or evening when the sun isn't on them

best moved or planted november to march, you would have a job to get a young leilandi water loged , I like your idear of thuja Pam, they are lovley and aromatic, also evergreen, but they can grow to 20m'
haveing said that I would put up with a golden leilandi as they are better looking than the green and do not grow fast like the green.