My thoughts here are more: use 850nm Led than 940nm.
850nm are just a little visible but more accurate than 940nm who is invisible to our eyes.
850nm provides better field view at night than 940nm.
And of course 99% of the standard cams are made for 850 nm.
To the question : Can I use similar Led to original ones : Answer is yes, even if they are quite different.
Just use the same format/enclosure/diameter.
As in most os cases they are wired in group of 3/4 dépending of the power voltage applied to the board, there are not much risks here.
Made it often for customers and any issues since years. But 850nm, remember.
Tips and tricks: to isolate the faulty ones, just a simple controller in position "diode test" will very usefull find the bad ones in the group.
Hope this helps.
