I made these crosshairs from scratch (hope you can't tell).  Took me a while, but I think it was worth it. 

Installation:
Copy the "sprites" folder from within the zip file into your "Halflife/NS/" folder.  It should overwrite files.
If you wouldn't like a particular crosshair (or all) to show up in game, simply copy the text file from within the backup
folder and paste it into your "NS/sprites" folder.

Credits:
Crosshairs: Shazbot
Ideas:
6john6doe6
Sykotic
Dragon_Mech
MR.JEBURTO

Hope you like 'em and enjoy!