All scientist outfits can be repaired with the scientist outfit, lab technician outfit, Enclave scientist outfit, Vault lab uniform, and Doctor Li's outfit.
The lab technician outfit is nearly identical with the scientist outfit with the only noticeable difference being a dark blue undershirt instead of a teal one. It is worn by scientists in Rivet City.
The easiest way to obtain it would be from Anna Holt in the Rivet City science lab. Doctor Lesko encountered during the Those! quest is also wearing one of these, should you decide to kill him after completing the quest. There is also a unique lab technician outfit (Broken Steel add-on) worn by the Enclave doctor inside the medical bay in the Mobile Base Crawler.
In Fallout: New Vegas the lab technician outfit is worn by Dr. Kemp in Camp McCarran concourse. It can be acquired by reverse-pickpocketing higher DT armor or by killing him.
Enclave scientist outfit
The Enclave scientist outfit has a similar look to the radiation suit, but it is white with an orange-tinted plexiglas helmet. It is worn only by Enclave scientists, who do not respawn when killed. Therefore, there are only so many of them. Use the other scientist outfits to repair them.
Several Enclave camp locations may spawn a scientist with this outfit.
All-purpose science suit
The all-purpose science suit is identical in all but name with the Enclave scientist outfit. The suit was originally cut from Fallout 3, but was added into Fallout: New Vegas with patch 1.2.0.31x and can be found in the Followers of the Apocalypse safehouse.