Just use what is known to work. A2 metre radio in AM mode with a directional antenna. I have built a small moxon, tape measure yagi and a simple dipole. A 10,20, 30 db attenuator can be helpful.
Not all interference extends above 200 mhz, however if you can hear the same interference around 300 to 340mhz on AM you are pretty close to the source. 440mhz has similar characteristics in terms of finding close by interference. From experience the interference has to be pretty bad to extend above 200mhz. It mostly powerline arcs that extend this far.
I would starting cruising around your blocks in the neighbourhood with the whip antenna and attenuator. its amazing how you can almost nail the source of the interference just using nulls and attenuation if you are persistent.
Good luck.
...or would I be just as well off using my 2 meter Kenwood HT with the "proper" direction finding antenna? Then what is the recommended broad band noise hunting antenna for 2 meters?