The Anushasan Parva of Mahabharat mentions many dignitaries that are praiseworthy and names a few rishis:
After this I shall recite the names of those foremost Rishis who are known as Manavas. They are Yavakrita, Raibhya, Arvavasu, Paravasu, and Aushija, Kakshivat, and Vala the son of Angiras. Then comes Kanwa the son of the Rishi Medhatithi, and Varishada.
I found the stories of the first four here and know about Kanva, and Aushija seems to be another name of Kakshivat (since his mother was Ushija) so I want to know more about the remaining rishis Vala and Varishada.
If it is any help the text further states:
They have sprung from Rudra and Anala and the Vasus. By reciting their names people obtain great benefits. Indeed, by doing good deeds on earth, people sport in joy in heaven, with the deities. These Rishis are the priests of Indra. They live in the east.