Have 2 low grade tumors in the lungs and kidney with the lungs being primary.. would the next tumor they are going to biopsy be low grade as well ?

Lung Tumor: If i understand you correctly, you have a low grade lung tumor that has spread to the kidney, and not two separate tumors. As a general rule, a new metastasis will have the same morphology as the original tumor, but, even so, a metastatic lung tumor, even if it is "low grade, " requires immediate treatment, which may include surgery, chemotherapy and irradiation, depending on the diagnosis.

Not sure: The two lung tumors probably represent primary source of kidney mets. When there is only one site of metastatic disease, it is essential to evaluate primary for resection since further mutations will occur resulting in other organs of metastatic disease . Even though mets are low grade, higher grade lesions will develop and spread. With primary removed only kidney lesions remain for removal.