Heat resistant paints for metal smoking pipe
After looking into a few options that you might have already seen I think this will be a safety concern for yourself that you should best avoid. 

I am not insinuating what you do with the pipe but this discussion has come up before on a few forums about pipe smoking. 


Grasscity - Opinion on spray painting metal pipe
Drug Forum - Paint/Color a Metal One-Hitter2
Marijuana.com - Metal Pipe Paint -- Overly Paranoid?2


The consensus is don't risk doing it. From a general standpoint you cannot guarantee that the paint, once sealed/cured/dried etc, wont react in some way once heated regardless of the temperature limit. I know this does not meet your threshold but consider the MSDS for Rustoleum High Heat Spray which is designed for resistance extreme temperatures (1200ºF). It list several chemicals that are known carcinogens1. It is also worth noting these types of paints were not meant for direct flame contact. 

Sure you might not paint near the bowl.. but why risk it anyway? If you are trying to personalize it it might just be better to buy one that already has what you are looking for. I don't know what the motivation for painting it though. Personalization was just a guess 



1. I understand those chemicals are listed as present in the can before sprayed but surely enough of them are still present in the paint and have the potential to be released later.

2. This forum post goes a little off topic but the sentiment of not painting a metal pipe is shared.