@aniko I have to agree that if you use Campbell, spell it correctly.
Elsewise, you'll know the right name when you find it. As you did with your first. I say this after 3 girls,
and I feel girl names are more difficult. There are way too many bad associations.
Anyway, my husband and I are both J, Our older daughters are K, and the baby is an A. Some people were mighty pissed we didn't do another K. However, we didn't like any non taken options for K, and originally, I was going to use a C with my second to avoid this.
However, the baby our OB delivered moments before had the same name with a C, so we used the K my husband wanted. Considering they were already sharing a birthday, birthplace, and practically a birth time, it seemed wise to spell the name as differently as possible from them. They also doubled a constant that we didn't.
With our first, I knew immediately. With our second, my husband suggested something I didn't like right away, but within 2 days, I decided that was it, and I loved it. With our third, it took a lot of time, and there were many names we were ok with until we found the right one.
Sometimes, we try to settle because it seems we have looked at everything 100 times already. You will find the name eventually. Mind you with each of my daughtera names, my MIL actively hated the names very vocally, but it didn't matter because they were the name. (All of my daughters have beautiful names, and she is the only one who has ever thought the names were bad) she wanted Kathryn, Elizabeth, Jessica, Leah, or Lilly. All of which are taken in our families, too.
Lastly, to find my last daughters name, I looked at a rarest names list. It worked.