Anita,
You asked, “How does one go about looking for oncologists who specialize in NETs?”
There are some NET specialists/surgeons that are quite well known in the NET world because they are well respected, very knowledgeable, and have helped many. I will list a few that I am aware of:
Dr. Eric Liu in Denver, Dr. Jonathan Strosberg at Moffitt in Tampa where I am being treated, Dr. Jason Starr at Mayo in Jacksonville FL., Dr. Thor Halfdanarson at Mayo in Rochester Mn. These are just a few – and three of them are on the east side of the US. And other patients may also mention who they are being treated by.

Here at Mayo Jacksonville we have a monthly Support Group Meeting via. Zoom and this next month Dr. Jason Starr will be the speaker. Come, join, and ask questions. Dr Starr is very knowledgeable, and you will learn a lot. It is always the first Thursday of the month, so the next meeting will be August 7th at 5:30 PM. Here is a link that should allow you to pre-register for the meeting.
https://mchealth.zoom.us/meeting/register/wcWv-MZNTAOg_NU5Xw8jLQ
I may miss the August meeting due to travel, but hope you can join in.