ATA can be contacted at ATAworks@yahoo.com. (Heres a good thread to give you background to it:http://forum.whitearmor.net/index.php?showtopic=7239&hl=question+ata)
TE, well I dont know any info on bying his helmets.
TE2, is made by XXXXXX, a cool guy. Hes around these boards.
Troopermaster or TM, a very nice guy, makes a helmet that is very popular, and hes on these boards.
JoeR are selling awesome looking ROTJ helmets. Hes also on these boards.
If I got anything wrong, then please correct me guys.
Cheers