Here is a list of components I prefer and recommend but will gladly use others if preferred by a customer.
Zeiss
Swarovski Optik
Nightforce Optics
Leupold
Brux
Krieger
Hart
Lilja
Bartlein
Rock Creek
Manners
McMillan
Precision Stock Works
Brown Precision
MPI
Borden
BAT
Surgeon
Kelbly
Lawton
Defiance
Pierce
Stiller
PT&G
Cerakote
Sandstrom
Redding
Wilson
Newlon Precision
Berger
Barnes
Nosler
Sierra
Hornady